P1010Association between left atrial fibrosis detected by cardiac magnetic resonance and endocardial electroanatomic mapping in the evaluation of the electrophysiological substrate in atrial fibrillation

Background

Atrial fibrillation (AF) is related to left atrial fibrosis, but its identification by late magnetic resonance imaging (LGE) with gadolinium (LGE) persists in controversy due to heterogeneous results in its correlation with the electroatomic map (EAM) and the difficulty of perform histological studies in humans.

Purpose

We try to examine the point-by-point association between high density EAM and LGE-MRI using an automatic and reproducible method.

Methods

A LGE-MRI was performed in 16 patients prior to ablation. Three different areas were established depending on the intensity of normalized enhancement for each patient according to their blood group with the image intensity ratio (IIR) (healthy <1.20, border area (BZ) ≥1.20 <1.32 and scar ≥1.32). The high density electroanatomic maps of the left atrium (LA) were projected onto the MRI, obtaining an automatic correlation point by point.

Results

The study obtained significant differences (p < 0.001) between voltage (mV) and CV (mm/ms) among healthy, BZ and scar areas, as well a significant inverse correlation (p < 0.001) between voltage and IIR (R=-0.39). It obtained too a significant correlation between CV and IIR (R=-0.24), but this showed a greater correlation in those patients who have the least dilated LA (p = 0.02).

Conclusions

LGE-MRI and EAM showed good correlation in delineating potential pathologic substrate in AF, but left atrium dilation could reduce the performance of the CMR in this task. Conduction velocity could be more sensitive than voltage and LGE-MRI to detect incipient substrate in AF.

Voltage and conduction velocity values Area /IIR Velocity (mm/ms) Voltage (mV) I / <.20 1.036(0.913-1.158) 1.593(1.489-1.696) 2 / ≥1.20 and <1.32 0.722(0.590-0.850) 0.792 (0.649-0,935) 3 / ≥1.32 0.623(0.473-0,733) 0.444(0.245-0.642) Voltage and conduction velocity values in the three areas of the LGE-RMN.

Abstract Figure. Correlation among voltage, VC and LA

HNF4a transcription is a target of trichloroethylene toxicity in the embryonic mouse heart

In exploration of congenital heart defects produced by TCE, Hepatocyte Nuclear Factor 4 alpha (HNF4a) transcriptional activity was identified as a central component. TCE exposure altered gene transcription in the chick heart in a non-monotonic pattern where only low dose exposure inhibited transcription by HNF4a. As the chick embryo is non-placental, we examine here HNF4a as a target of TCE in developing mouse embryos. Benfluorex and Bi6015, published agonist and antagonist, respectively, of HNF4a were compared to low dose TCE exposure. Pregnant mice were exposed to 10 ppb (76 nM) TCE, 5 μM Benfluorex, 5 μM Bi6015, or a combination of Bi6015 and TCE in drinking water. Litters (E12) were collected during a sensitive window in heart development. Embryonic hearts were collected, pooled for extraction of RNA and marker expression was examined by quantitative PCR. Multiple markers, previously identified as sensitive to TCE exposure in chicks or as published targets of HNF4a transcription were significantly affected by Benfluorex, Bi6015 and TCE. Activity of TCE and both HNF4a-specific reagents on transcription argues that HNF4a is a component of TCE cardiotoxicity and likely a proximal target of low dose exposure during development. The effectiveness of these reagents after delivery in maternal drinking water suggests that neither maternal metabolism, nor placental transport is protective of exposure.

Obesity and weight misperception among adults in the Eastern Caribbean Health Outcomes Research Network (ECHORN) Cohort Study

OBJECTIVE

Prior studies have suggested that weight misperception - underestimating one's actual weight - may be associated with reduced engagement in weight loss programmes, decreasing the success of initiatives to address obesity and obesity-related diseases. The purpose of this study was to examine the factors associated with weight misperception among Eastern Caribbean adults and its influence on engagement in weight control behaviour.

METHODS

Data from the Eastern Caribbean Health Outcomes Research Network (ECHORN) Cohort Study were analysed (adults aged 40 and older, residing in the US Virgin Islands, Puerto Rico, Barbados and Trinidad). Weight misperception is defined as participants who under-assess their weight measured by body mass index (BMI). Multivariable logistic regression (n = 1,803 participants) was used to examine the association of weight misperception with BMI category, age, gender, education, history of non-communicable disease and attempt to lose weight.

RESULTS

Weight misperception was common, with 54% of overweight (BMI 25-29 kg m-2), and 23% of obese class I (BMI 30-34.9 kg m-2) participants under-assessing their actual weight. Participants with higher levels of education, versus lower, had decreased odds of weight misperception (OR 0.5, p < 0.001). There were no significantly reduced odds of weight misperception in women versus men (OR 1.13, p = 0.367) or in individuals with history of diabetes versus none (OR 0.88, p = 0.418). Participants with weight misperception had 85% (p < 0.0001) lower odds of attempting weight loss than those with accurate weight perception.

CONCLUSION

Weight misperception is common among adults with overweight and obesity in the Eastern Caribbean and is associated with lower likelihood of attempting weight loss. Obesity interventions, targeting similar populations, should incorporate approaches for addressing weight misperception to achieve measurable success.

Trichloroethylene perturbs HNF4a expression and activity in the developing chick heart

Exposure to trichloroethylene (TCE) is linked to formation of congenital heart defects in humans and animals. Prior interactome analysis identified the transcription factor, Hepatocyte Nuclear Factor 4 alpha (HNF4a), as a potential target of TCE exposure. As a role for HNF4a is unknown in the heart, we examined developing avian hearts for HNF4a expression and for sensitivity to TCE and the HNF4a agonist, Benfluorex. In vitro analysis using a HNF4a reporter construct showed both TCE and HFN4a to be antagonists of HNF4a-mediated transcription at the concentrations tested. HNF4a mRNA is expressed transiently in the embryonic heart during valve formation and cardiac development. Embryos were examined for altered gene expression in the presence of TCE or Benfluorex. TCE altered expression of selected mRNAs including HNF4a, TRAF6 and CYP2C45. There was a transition between inhibition and induction of marker gene expression in embryos as TCE concentration increased. Benfluorex was largely inhibitory to selected markers. Echocardiography of exposed embryos showed reduced cardiac function with both TCE and Benfluorex. Cardiac contraction was reduced by 29% and 23%, respectively at 10 ppb. The effects of TCE and Benfluorex on autocrine regulation of HNF4a, selected markers and cardiac function argue for a functional interaction of TCE and HNF4a. Further, the dose-sensitive shift between inhibition and induction of marker expression may explain the nonmonotonic-like dose response observed with TCE exposure in the heart.

Cardiac Regeneration in the Human Left Ventricle After CorMatrix Implantation

CorMatrix is an organic extracellular matrix (ECM) derived from porcine small intestine submucosa and is used for pericardial closure and cardiac tissue repair. During explantation of a HeartMate II (Thoratec Corp, Pleasanton, CA) left ventricular assist device (LVAD) because of infection, CorMatrix was used to repair the left ventricular apex and aorta. Three months later, a HeartWare HVAD (HeartWare International, Inc, Framingham, MA) was implanted for recurrent heart failure. Excised apical CorMatrix samples showed cardiac tissue remodeling with viable cardiomyoblasts similar to native myocardium. Excised CorMatrix from the aorta showed organization of collagen and elastin similar to native aortic tissue.

Inhibition of Ciliogenesis Promotes Hedgehog Signaling, Tumorigenesis, and Metastasis in Breast Cancer

Primary cilia are chemosensors that play a dual role to either activate or repress Hedgehog signaling, depending on presence or absence of ligand, respectively. While inhibition of ciliogenesis has been shown to be characteristic of breast cancers, the functional consequence is unknown. Here, for the first time, inhibition of ciliogenesis led to earlier tumor formation, faster tumor growth rate, higher grade tumor formation, and increased metastasis in the polyoma middle T (PyMT) mouse model of breast cancer. In in vitro model systems, inhibition of ciliogenesis resulted in increased expression of Hedgehog-target genes through a mechanism involving loss of the repressor form of the GLI transcription factor (GLIR) and activation of Hedgehog target gene expression through cross-talk with TGF-alpha (TGFA) signaling. Bioinformatics analysis revealed that increased Hedgehog signaling is frequently associated with increased TGFA; signaling in patients with triple-negative breast cancers (TNBC), a particularly aggressive breast cancer subtype. These results identify a previously unrecognized role for inhibition of ciliogenesis in breast cancer progression. This study identifies inhibition of ciliogenesis as an important event for activation of Hedgehog signaling and progression of breast cancer to a more aggressive, metastatic disease.Implications: These findings change the way we understand how cancer cells turn on a critical signaling pathways and a provide rationale for developing novel therapeutic approaches to target noncanonical Hedgehog signaling for the treatment of breast cancer. Mol Cancer Res; 15(10); 1421-30. ©2017 AACR.

Use of second generation supra-glottic airway devices during laparoscopic cholecystectomy: a prospective, randomized comparison of LMA Proseal™, LMA SupremeTM and igel™

INTRODUCTION

Supra-glottic airway devices (SADs) with an inbuilt drain channel, such as the LMA Proseal™ (LMA-P), LMA SupremeTM (LMA-S) and i-gel™ (i-gel), have been used for laparoscopic cholecystectomy. We compared safety, efficacy, and ease of use, as well as the incidence of adverse events between these devices.

METHODS

One hundred and eighty adult, ASA 1-3 patients scheduled to undergo elective cholecystectomy under general anesthesia were randomly allocated to one of three groups: LMA-P, LMA-S or i-gel. The primary outcome was to evaluate oropharyngeal leak pressure (OLP). Secondary outcomes were to evaluated speed of insertion, ease of insertion of the device and the drain tube, as well as the incidence of intraoperative adverse events and postoperative oropharyngeal discomfort (POPD).

RESULTS

Mean OLP was significantly higher for LMA-P (LMA-P 30.87; i-gel 29.28; LMA-S 29.02 cm H₂0, P = 0.007). OLP was correlated with a higher maximum tidal achieved volume (P = 0.025). Insertion times were shorter for the i-gel, which was 1.7 s faster to insert than LMA-P (P = 0.04). The success rate on first attempt was higher for the LMA-S (P = 0.004). The drain tube was easily inserted in the LMA-S group (p < 0.001). I-gel showed higher sore throat scoring 2 hours postoperatively (P = 0.008) and reported slower POPD decrease during that time (P < 0.001).

CONCLUSIONS

Among SAD's, LMA-S is the easiest to insert (including the drain tube), LMA-P achieved the best leak pressure, and i-gel fastest to insert, although associated with the worst POPD scoring.

Systemic chemotherapy (SC) before cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) in patients with peritoneal mucinous carcinomatosis of appendiceal origin (PMCA)

BACKGROUND

The role of SC before CRS/HIPEC for patients with PMCA is unclear. This study explores the effect of SC prior to CRS/HIPEC on overall survival (OS) in patients with PMCA.

METHODS

72 patients with recently diagnosed PMCA who underwent CRS/HIPEC were identified from a prospective database. Thirty patients had SC before CRS/HIPEC (Group 1) and 42 did not (Group 2). Patients who were referred to our center after multiple lines of SC were excluded from this analysis. OS was estimated.

RESULTS

Median follow-up was 3.2 years. Groups were similar regarding lymph node positivity, postoperative SC and rate of complete cytoreduction. Twenty-four (80%) patients in Group 1 and 21 (50%) in Group 2 had high grade histology (HG) (p = 0.01). OS from CRS/HIPEC at 1, 2, and 3 years was 93, 68, 51% in Group 1 and 82, 64, 60% in Group 2, respectively (p = 0.74). Among HG patients 3-year survival was 36% in the SC group vs. 35% in the group without SC (p = 0.67). The 3-year OS for patients with low grade (LG) tumors was 100% in the SC group vs. 79% in the group with no prior SC (p = 0.26). Among patients with signet ring cell (SRC) histology, 1, 2 and 3-year survival was 94, 67 and 22% in the SC group vs. 43, 14, 14% in the group with no SC, respectively (p = 0.028). There were only 6 patients with LG PMCA who received prior SC.

CONCLUSIONS

Preoperative SC could improve the prognosis of patients with high-grade PMCA with SRC histology.

Microbial specialists in below-grade foundation walls in Scandinavia

Below-grade foundation walls are often exposed to excessive moisture by water infiltration, condensation, leakage, or lack of ventilation. Microbial growth in these structures depends largely on environmental factors, elapsed time, and the type of building materials and construction setup. The ecological preferences of Actinomycetes (Actinobacteria) and the molds Ascotricha chartarum, Myxotrichum chartarum (Ascomycota), Geomyces pannorum, and Monocillium sp. (Hyphomycetes) have been addressed based on analyses of 1764 samples collected in below-grade spaces during the period of 2001-2012. Our results show a significant correlation between these taxa and moist foundation walls as ecological niches. Substrate preference was the strongest predictor of taxa distribution within the wall, but the taxa's physiological needs, together with gradients of abiotic factors within the wall structure, also played a role. Our study describes for the first time how the wall environment affects microbial growth.

Chest compression depth and survival in out-of-hospital cardiac arrest

AIM

Outcomes from out-of-hospital cardiac arrest (OHCA) may improve if rescuers perform chest compressions (CCs) deeper than the previous recommendation of 38-51mm and consistent with the 2010 AHA Guideline recommendation of at least 51mm. The aim of this study was to assess the relationship between CC depth and OHCA survival.

METHODS

Prospective analysis of CC depth and outcomes in consecutive adult OHCA of presumed cardiac etiology from two EMS agencies participating in comprehensive CPR quality improvement initiatives.

ANALYSIS

Multivariable logistic regression to calculate adjusted odds ratios (aORs) for survival to hospital discharge and favorable functional outcome.

RESULTS

Among 593 OHCAs, 136 patients (22.9%) achieved return of spontaneous circulation, 63 patients (10.6%) survived and 50 had favorable functional outcome (8.4%). Mean CC depth was 49.8±11.0mm and mean CC rate was 113.9±18.1CCmin(-1). Mean depth was significantly deeper in survivors (53.6mm, 95% CI: 50.5-56.7) than non-survivors (48.8mm, 95% CI: 47.6-50.0). Each 5mm increase in mean CC depth significantly increased the odds of survival and survival with favorable functional outcome: aORs were 1.29 (95% CI 1.00-1.65) and 1.30 (95% CI 1.00-1.70) respectively.

CONCLUSION

Deeper chest compressions were associated with improved survival and functional outcome following OHCA. Our results suggest that adhering to the 2010 AHA Guideline-recommended depth of at least 51mm could improve outcomes for victims of OHCA.

CHF5074 Reduces Biomarkers of Neuroinflammation in Patients with Mild Cognitive Impairment: A 12-Week, Double-Blind, Placebo-Controlled Study

As neuroinflammation is an early event in the pathogenesis of Alzheimer's disease, new selective anti-inflammatory drugs could lead to promising preventive strategies. We evaluated the safety, tolerability, pharmacokinetics and pharmacodynamics of CHF5074, a new microglial modulator, in a 12-week, double-blind, placebo-controlled, parallel groups, ascending dose study involving 96 MCI patients. Subjects were allocated into three successive study cohorts to receive ascending, titrated doses of CHF5074 (200, 400 or 600 mg/day) or placebo. Vital signs, cardiac safety, neuropsychological performance and safety clinical laboratory parameters were assessed on all subjects. Plasma samples were collected throughout the study for measuring drug concentrations, soluble CD40 ligand (sCD40L) and TNF-α. At the end of treatment, cerebrospinal fluid (CSF) samples were optionally collected after the last dose to measure drug levels, β-amyloid1-42 (Aβ42), tau, phospho-tau181, sCD40L and TNF-α. Ten patients did not complete the study: one in the placebo group (consent withdrawn), two in the 200-mg/day treatment group (consent withdrawn and unable to comply) and seven in the 400-mg/day treatment group (five AEs, one consent withdrawn and one unable to comply). The most frequent treatment-emergent adverse events were diarrhea, dizziness and back pain. There were no clinically significant treatment-related clinical laboratory, vital sign or ECG abnormalities. CHF5074 total body clearance depended by gender, age and glomerular filtration rate. CHF5074 CSF concentrations increased in a dose-dependent manner. At the end of treatment, mean sCD40L and TNF-α levels in CSF were found to be inversely related to the CHF5074 dose (p=0.037 and p=0.001, respectively). Plasma levels of sCD40L in the 600-mg/day group were significantly lower than those measured in the placebo group (p=0.010). No significant differences between treatment groups were found in neuropsychological tests but a positive dose-response trend was found on executive function in APOE4 carriers. This study shows that CHF5074 is well tolerated in MCI patients after a 12-week titrated treatment up to 600 mg/day and dose-dependently affects central nervous system biomarkers of neuroinflammation.

Ethnicity and elevated liver transaminases among newly diagnosed children with type 2 diabetes

BACKGROUND

To examine the influence of ethnicity on liver transaminases among adolescents with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective medical chart review of 57 (30 males and 27 females) newly diagnosed patients with T2DM. Ethnicity was determined by self-report and height, weight, body mass index (BMI) and glycosylated hemoglobin (HbA1c) were obtained using standard clinical procedures. Fasting levels of alanine aminotransaminase (ALT) and aspartate aminotransferase (AST) were collected prior to the initiation of any therapy.

RESULTS

Age, gender, height, weight, BMI, and HbA1c did not differ between ethnic groups. Compared to African-Americans, Hispanics had significantly higher ALT (23.9 ± 3.4 vs. 107.8 ± 20.3, p=0.002) and AST (17.7 ± 2.5 vs. 71.1 ± 15.7, p<0.001) and were significantly more likely to have ALT values above the upper limit of normal (20% vs. 71%, p=0.005) and twice the upper limit of normal (0% vs. 39%, p=0.05) as well as AST values above the upper limit of normal (0% vs. 53%, p=0.002). No differences in ALT or AST were found between Hispanics and non-Hispanic whites or between African-Americans and non-Hispanic whites.

CONCLUSIONS

These preliminary findings suggest that Hispanic children with T2DM may be at higher risk for developing non-alcoholic fatty liver disease and indicate that a comprehensive hepatic evaluation is warranted in this population. Future studies that incorporate more precise and proximal measures of liver health are warranted in this population.

Prevention of histamine formation in cheese by bacteriocin-producing lactic Acid bacteria

The susceptibility of 13 amine-forming lactobacilli to several bacteriocins was investigated by an agar diffusion assay. All strains were susceptible to nisin and to five bacteriocins of enterococcal origin. Pediocin PA-1, bavaricin A, lactococcin A, and a bacteriocin from Enterococcus faecalis 1061 did not show inhibitory activity. Two bacteriocin-producing enterococci and a nisin-producing Lactococcus lactis strain were employed as starters in separate cheese-making experiments. Outgrowth of histamine producer Lactobacillus buchneri St2A, which was added to the milk at levels of up to 190 CFU/ml, was almost completely inhibited. No histamine formation was detected in the cheeses made with bacteriocin-producing starters. In the control cheese without bacteriocin, St2A reached levels of 1.1 x 10(sup8) CFU/g, and 200 mg of histamine per kg was found after 4 months of ripening. To our knowledge, this is the first report of bacteriocin-mediated inhibition of histamine formation in foods.

Effect of planting date on Lissorhoptrus oryzophilus (Coleoptera: Curculionidae) density-yield relationship on rice in southeastern Texas

Results of planting date and insecticide efficacy experiments targeting Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) on rice, Oryza sativa L., in southeastern Texas between 2002 and 2007 were used to determine density-yield relationships as a function of planting date. Soil core samples were collected on two dates during main crop development to estimate immature L. oryzophilus populations followed by main and ratoon crop harvests. Analysis of covariance (ANCOVA) revealed that planting date did not affect the density-main crop yield relationship during most years and that these relationships varied substantially among years. For ratoon crop yield, an effect of main crop L. oryzophilus immature infestation was detected during some years, but the real effect of these populations on ratoon crop yield remains unclear. Using estimates of yield reduction per L. oryzophilus immature, economic injury levels were calculated. Main crop yields from treated plots and first soil core sample L. oryzophilus immature populations from untreated plots were significantly higher in plots planted at recommended dates than in plots planted earlier or later. This suggests that the presence of high populations of reproductive L. oryzophilus coincides with the period when rice fields planted at optimum dates are flooded. Results from this study reinforce the importance of managing L. oryzophilus populations when planting rice at recommended dates in southeastern Texas.

Regionalization of epididymal duct and epithelium in rats and mice by automatic computer-aided morphometric analysis

AIM

To establish a rat and mouse epididymal map based on the use of the Epiquatre automatic software for histologic image analysis.

METHODS

Epididymides from five adult rats and five adult mice were fixed in alcoholic Bouin's fixative and embedded in paraffin. Serial longitudinal sections through the medial aspect of the organ were cut at 10 microm and stained with hematoxylin and eosin. As determined from major connective tissue septa, nine subdivisions of the rat epididymis and seven for the mouse were determined, consisting of five sub-regions in the caput (rat and mouse), one (mouse) or three (rat) in the corpus and one in the cauda (rat and mouse). Using the Epiquatre software, several tubular, luminal and epithelial morphometric parameters were evaluated.

RESULTS

Statistical comparison of the quantitative parameters revealed regional differences (2-5 in the rat, 3-6 in the mouse, dependent on parameters) with caput regions 1 and 2 being largely distinguishable from the similar remaining caput and corpus, which were in turn recognizable from the cauda regions in both species.

CONCLUSION

The use of the Epiquatre software allowed us to establish regression curves for different morphometric parameters that can permit the detection of changes in their values under different pathological or experimental conditions.

Quality of care in institutionalized deliveries: the paradox of the Dominican Republic

OBJECTIVES

To better understand the paradox in the Dominican Republic of a relatively high maternal mortality ratio despite nearly universal institutionalized deliveries with trained attendants, a rapid assessment using an adaptation of the strategic assessment method was conducted.

METHODS

A multi-disciplinary team reviewed national statistics and hospital records, inventoried facilities, and observed peripartum client-provider interactions at 14 facilities.

RESULTS

The major referral hospitals, where more than 40% of births in the country occur, were overcrowded and understaffed, with inexperienced residents overseeing care provided by medical students, interns and nurses. Uncomplicated labor and deliveries were overmedicalized, while complicated ones were not managed appropriately; emergencies were not dealt with in a timely fashion. In the peripheral hospitals physicians were seldom present and clients were either turned away or delivered by unprepared nursing staff. Providers in the busiest facilities suffered from compassion fatigue, and were demoralized and overworked. In all facilities, quality of care was lacking and the delivery and birthing process was dehumanized.

CONCLUSIONS

Access and availability of institutional delivery alone is not enough to decrease MMR, it is also the quality of emergency obstetric care that saves lives.

Diffusive alignment of the magnetic field in active regions of plasmas

Regions of high magnetic field within plasmas tend to keep this field aligned in a dominant direction. This occurs both in observed phenomena and in simulations of kinematic and nonlinear dynamos. Although most of this effect is due to the particular dynamics of each case, magnetic diffusion also plays an important role. It is shown here that the unitary magnetic field vector satisfies a certain estimate that bounds its possible variations. The dependence of the bound on the plasma parameters is analyzed.

Taking the 5000 year old "Jettböle skeletons" out of the closet: a palaeo-medical examination of human remains from the Aland (Ahvenanmaa) Islands

Results of a somewhat preliminary bioanthropological study on the skeletal material from the Pitted ware site of jettböle, excavated in the parish of jomala, Aland (Ahvenanmaa) Islands, some 85-90 years ago are presented, and the causes for the disorderly distribution, including the possibility of cannibalism, are discussed.

Occurrence of Listeria monocytogenes and other Listeria spp. in raw caprine milk

Samples of caprine milk from bulk tanks of 405 farms in central Spain were analyzed for Listeria spp. once per season over a 1-yr period. Listeria monocytogenes and Listeria innocua were detected in 2.56 and 1.73% of the 1445 samples, respectively. Listeria ivanovii (0.21% samples) and Listeria seeligeri (0.07% samples) were rarely isolated. Only 6 milk samples were contaminated by more than one Listeria species. Most farms (92.59%) produced milk that was apparently free from L. monocytogenes throughout the sampling period, and 88.40% produced milk that was apparently free from Listeria spp. Milk contamination by Listeria spp. was seasonal; incidence in autumn (9.33%) and winter (5.14%) samples was higher than incidence in spring (0.85%) and summer (0.85%) samples. Occurrence of Listeria spp. was lower in samples from mountain farms (1.25%) than in samples from plateau farms (7.03%).

Purification and characterization of enterocin 4, a bacteriocin produced by Enterococcus faecalis INIA 4

A simple two-step procedure was developed to obtain pure enterocin 4, a bacteriocin produced by Enterococcus faecalis INIA 4. Chemical and genetic characterization revealed that the primary structure of enterocin 4 is identical to that of peptide antibiotic AS-48 from Enterococcus faecalis S-48. In contrast to the reported inhibitory spectrum of AS-48, enterocin 4 displayed no activity against gram-negative bacteria.

Thyroid imaging with Tc-99m MIBI in patients with solitary cold single nodules on pertechnetate imaging

Thyroid imaging was performed in 30 patients with the standard pertechnetate technique, as well as with Tc-99m MIBI using a double-phase acquisition protocol. All patients had normal thyroid function confirmed by hormone measurements and cold solitary thyroid nodules, which were evaluated by pertechnetate scanning. Tc-99m MIBI scans were reported as showing cold (N = 14), warm (N = 7), or hot (N = 9) nodules. Nodule classification was made according to fine needle aspiration biopsy findings in 20 patients. The remaining 10 proceeded to surgery and had histopathologic confirmation of their lesions. Although all cold nodules with Tc-99m MIBI were cystic, six of the warm nodules were benign lesions. No histologically proven benign nodule was hot with Tc-99m MIBI. Of the hot nodules, seven were suspicious for follicular carcinoma with fine needle aspiration biopsy (N = 3), or had histologically proven papillary carcinoma (N = 4). Delayed images in five of seven of these lesions showed nodular retention of the radiopharmaceutical. In conclusion, double-phase Tc-99m MIBI scanning of the thyroid gland could be helpful in the preoperative assessment of patients with cold solitary thyroid nodules in order to evaluate the malignancy probability of these lesions.