Deep Learning-Based Natural Language Processing to Automate Esophagitis Severity Grading from the Electronic Health Records

PURPOSE/OBJECTIVE(S)

Radiotherapy (RT) toxicities can impair survival and quality-of-life, yet their risk factors and optimal management are under-studied. Real-world evidence holds enormous potential to improve our understanding of RT adverse events, but this information is often only documented in clinic notes and cannot, at present, be automatically extracted. To address this unmet need, we developed natural language processing (NLP) algorithms to automatically identify the presence and severity of esophagitis from notes of patients treated with thoracic RT.

MATERIALS/METHODS

Our corpus consisted of (1) a gold-labeled dataset of 1524 clinic notes from 124 lung cancer patients treated with RT (in-domain), manually annotated for CTCAE v5.0 esophagitis grade, and (2) a silver-labeled dataset of 2420 notes from 1832 patients on whom toxicity grades had been collected as structured data during clinical care. We developed a fine-tuning pipeline for pre-trained BERT-based neural models for 3 tasks: 1) classifying the presence of esophagitis, 2) classifying grade 0-1 vs. > = 2 esophagitis and 3) classifying grade 0 vs. 1 vs. 2-3. A note sectionizer was used to let the model focus on the most informative sections. Independent validation in a separate clinical cohort of esophageal cancer patients was selected for out-of-domain transferability testing. Such cohorts consist of a manually annotated dataset of 345 notes from 75 esophageal cancer patients treated with RT. We also report patient-level results by evaluating the maximum predicted grade per patient.

RESULTS

Fine-tuning PubmedBERT yielded the best-performing models. Performance is shown in the table. Selecting the most informative note sections (primarily Interval History, Assessment & Plan) during fine-tuning improved macro-F1 by > = 2% for all tasks. Including silver-labeled data improved the macro-F1 by > = 3% across all tasks.

CONCLUSION

To the best of our knowledge, this is the first effort to automatically extract toxicity severity according to CTCAE guidelines from clinic notes, providing proof-of-concept for NLP to support detailed toxicity reporting. Fine-tuning on note sections and leveraging silver-labeled data enabled promising performance despite small datasets, informing future research into NLP for automated toxicity monitoring. Future work will extend these methods to other cancer diagnoses and toxicities, and to toxicity risk prediction.

Pregnancy loss in major fetal congenital heart disease: incidence, risk factors and timing

OBJECTIVE

Fetuses with congenital heart disease (CHD) are at increased risk of pregnancy loss compared with the general population. We aimed to assess the incidence, timing and risk factors of pregnancy loss in cases with major fetal CHD, overall and according to cardiac diagnosis.

METHODS

This was a retrospective, population-level cohort study of fetuses and infants diagnosed with major CHD between 1997 and 2018 identified by the Utah Birth Defect Network (UBDN), excluding cases with termination of pregnancy and minor cardiovascular diagnoses (e.g. isolated aortic/pulmonary pathology and isolated septal defects). The incidence and timing of pregnancy loss were recorded, overall and according to CHD diagnosis, with further stratification based on presence of isolated CHD vs additional fetal diagnosis (genetic diagnosis and/or extracardiac malformation). Adjusted risk of pregnancy loss was calculated and risk factors were assessed using multivariable models for the overall cohort and prenatal diagnosis subgroup.

RESULTS

Of 9351 UBDN cases with a cardiovascular code, 3251 cases with major CHD were identified, resulting in a study cohort of 3120 following exclusion of cases with pregnancy termination (n = 131). There were 2956 (94.7%) live births and 164 (5.3%) cases of pregnancy loss, which occurred at a median gestational age of 27.3 weeks. Of study cases, 1848 (59.2%) had isolated CHD and 1272 (40.8%) had an additional fetal diagnosis, including 736 (57.9%) with a genetic diagnosis and 536 (42.1%) with an extracardiac malformation. The observed incidence of pregnancy loss was highest in the presence of mitral stenosis (< 13.5%), hypoplastic left heart syndrome (HLHS) (10.7%), double-outlet right ventricle with normally related great vessels or not otherwise specified (10.5%) and Ebstein's anomaly (9.9%). The adjusted risk of pregnancy loss was 5.3% (95% CI, 3.7-7.6%) in the overall CHD population and 1.4% (95% CI, 0.9-2.3%) in cases with isolated CHD (adjusted risk ratio, 9.0 (95% CI, 6.0-13.0) and 2.0 (95% CI, 1.0-6.0), respectively, based on the general population risk of 0.6%). On multivariable analysis, variables associated with pregnancy loss in the overall CHD population included female fetal sex (adjusted odds ratio (aOR), 1.6 (95% CI, 1.1-2.3)), Hispanic ethnicity (aOR, 1.6 (95% CI, 1.0-2.5)), hydrops (aOR, 6.7 (95% CI, 4.3-10.5)) and additional fetal diagnosis (aOR, 6.3 (95% CI, 4.1-10)). On multivariable analysis of the prenatal diagnosis subgroup, years of maternal education (aOR, 1.2 (95% CI, 1.0-1.4)), presence of an additional fetal diagnosis (aOR, 2.7 (95% CI, 1.4-5.6)), atrioventricular valve regurgitation ≥ moderate (aOR, 3.6 (95% CI, 1.3-8.8)) and ventricular dysfunction (aOR, 3.8 (95% CI, 1.2-11.1)) were associated with pregnancy loss. Diagnostic groups associated with pregnancy loss were HLHS and variants (aOR, 3.0 (95% CI, 1.7-5.3)), other single ventricles (aOR, 2.4 (95% CI, 1.1-4.9)) and other (aOR, 0.1 (95% CI, 0-0.97)). Time-to-pregnancy-loss analysis demonstrated a steeper survival curve for cases with an additional fetal diagnosis, indicating a higher rate of pregnancy loss compared to cases with isolated CHD (P < 0.0001).

CONCLUSIONS

The risk of pregnancy loss is higher in cases with major fetal CHD compared with the general population and varies according to CHD type and presence of additional fetal diagnoses. Improved understanding of the incidence, risk factors and timing of pregnancy loss in CHD cases should inform patient counseling, antenatal surveillance and delivery planning. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

The Value of Health Economics and Outcomes Research in Prosthetics and Orthotics

The demand has increased for evidence regarding the effectiveness and value of prosthetic and orthotic rehabilitation interventions. Clinicians and managers are under pressure to provide treatment recommendations and demonstrate effectiveness through outcomes. It is often assumed that rehabilitation interventions, including the provision of custom-made and custom-fit orthotic and prosthetic devices, are beneficial to patients. Assessing the value of orthotic and prosthetic services has become more critical to continue to ensure equitable access to needed services. Health economics and outcomes research methods serve as tools to gauge the value of prosthetic and orthotic rehabilitation interventions. The purpose of this article is to provide an overview of the current need of health economics and outcomes research in orthotics and prosthetics, to introduce common economic methods that assist to generate real-world evidence, and to discusses the potential value of economic methods for clinicians and clinical practice.

Correction: Sub-Doppler infrared spectroscopy of resonance-stabilized hydrocarbon intermediates: ν3/ν4 CH stretch modes and CH2 internal rotor dynamics of benzyl radical

Correction for ‘Sub-Doppler infrared spectroscopy of resonance-stabilized hydrocarbon intermediates: ν₃/ν₄ CH stretch modes and CH₂ internal rotor dynamics of benzyl radical’ by A. Kortyna et al., Phys. Chem. Chem. Phys., 2017, 19, 29812–29821.

Sub-Doppler infrared spectroscopy of resonance-stabilized hydrocarbon intermediates: ν3/ν4 CH stretch modes and CH2 internal rotor dynamics of benzyl radical

Highly reactive benzyl radicals are generated by electron dissociative attachment to benzyl chloride doped into a neon-hydrogen-helium discharge and immediately cooled to T_rot = 15 K in a high density, supersonic slit expansion environment. The sub-Doppler spectra are fit to an asymmetric-top rotational Hamiltonian, thereby yielding spectroscopic constants for the ground (v = 0) and first excited (v = 1, ν₃, ν₄) vibrational levels of the ground electronic state. The rotational constants obtained for the ground state are in good agreement with previous laser induced fluorescence measurements (LIF), with vibrational band origins (ν₃ = 3073.2350 ± 0.0006 cm^-1, ν₄ = 3067.0576 ± 0.0006 cm^-1) in agreement with anharmonically corrected density functional theory calculations. To assist in detection of benzyl radical in the interstellar medium, we have also significantly improved the precision of the ground state rotational constants through combined analysis of the ground state IR and LIF combination differences. Of dynamical interest, there is no evidence in the sub-Doppler spectra for tunneling splittings due to internal rotation of the CH₂ methylene subunit, which implies a significant rotational barrier consistent with partial double bond character in the CC bond. This is further confirmed with high level ab initio calculations at the CCSD(T)-f12b/ccpVdZ-f12 level, which predict a zero-point energy corrected barrier to internal rotation of ΔE_tun ≈ 11.45 kcal mol^-1 or 4005 cm^-1. In summary, the high-resolution infrared spectra are in excellent agreement with simple physical organic chemistry pictures of a strongly resonance-stabilized benzyl radical with a nearly rigid planar structure due to electron delocalization around the aromatic ring.

Operational Head-on Beam-Beam Compensation with Electron Lenses in the Relativistic Heavy Ion Collider

Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. To date, the implemented compensation scheme approximately doubled the peak and average luminosities.

Measurement of transient atomic displacements in thin films with picosecond and femtometer resolution

We report measurements of the transient structural response of weakly photo-excited thin films of BiFeO3, Pb(Zr,Ti)O3, and Bi and time-scales for interfacial thermal transport. Utilizing picosecond x-ray diffraction at a 1.28 MHz repetition rate with time resolution extending down to 15 ps, transient changes in the diffraction angle are recorded. These changes are associated with photo-induced lattice strains within nanolayer thin films, resolved at the part-per-million level, corresponding to a shift in the scattering angle three orders of magnitude smaller than the rocking curve width and changes in the interlayer lattice spacing of fractions of a femtometer. The combination of high brightness, repetition rate, and stability of the synchrotron, in conjunction with high time resolution, represents a novel means to probe atomic-scale, near-equilibrium dynamics.

The mechanism of ultrafast structural switching in superionic copper (I) sulphide nanocrystals

Superionic materials are multi-component solids with simultaneous characteristics of both a solid and a liquid. Above a critical temperature associated with a structural phase transition, they exhibit liquid-like ionic conductivities and dynamic disorder within a rigid crystalline structure. Broad applications as electrochemical storage materials and resistive switching devices follow from this abrupt change in ionic mobility, but the microscopic pathways and speed limits associated with this switching process are largely unknown. Here we use ultrafast X-ray spectroscopy and scattering techniques to obtain an atomic-level, real-time view of the transition state in copper sulphide nanocrystals. We observe the transformation to occur on a twenty picosecond timescale and show that this is determined by the ionic hopping time.

Abstracts from the North American Rhinology & Allergy Conference, February 3, 2011, Puerto Rico

INTRODUCTION

To establish the efficacy of bepotastine besilate ophthalmic solution (bepotastine) 1.5%, a dual acting histamine H1 receptor antagonist approved for treatment of ocular itching associated with allergic conjunctivitis, compared to placebo in relieving ocular itching and redness for subjects with active allergic rhinoconjunctivitis.

METHODS

A randomized, double-masked, placebo-controlled, confirmatory natural exposure study of bepotastine 1.5% and placebo was conducted during allergy season at 12 clinical sites throughout the U.S. Following a 7-day screening period, eligible subjects ≥12 years old were assigned in a 1:1 ratio to dosing OU b.i.d. either bepotastine 1.5% (n = 123) or placebo (n = 122). Subjects recorded instantaneous grades for their ocular symptoms prior to their next dose for 14 consecutive days. Clinically significant reduction in ocular sign or symptom grades between treatment groups required p ≤ 0.05 as determined by ANCOVA analysis.

RESULTS

Significant clinical effectiveness with bepotastine 1.5% was demonstrated over the 2-week treatment period in comparison to placebo in the intent-to-treat population for reducing mean instantaneous grades for both ocular itching (p = 0.007) and redness (p = 0.001). Investigator rating of efficacy over the 2-week treatment period across response categories was also superior for bepotastine 1.5% compared to placebo (p = 0.024). Only one subject discontinued participation in the study due to an adverse event.

CONCLUSIONS

These data support bepotastine 1.5% as an effective treatment for allergen-induced signs and symptoms in a clinical study designed to closely resemble the conditions under which patients with allergic rhinoconjunctivitis would require treatment.

piggyBac-like elements in the pink bollworm, Pectinophora gossypiella

A transgenic line of the pink bollworm, Pectinophora gossypiella, a key lepidopteran cotton pest, was generated previously using the piggyBac transposon IFP2 from Trichoplusia ni. Here we identified an endogenous piggyBac-like element (PLE), designated as PgPLE1, in the pink bollworm. A putatively intact copy of PgPLE1 (PgPLE1.1) presents the canonical features of PLE: inverted terminal repeats with three C/G residues at the extreme ends, inverted subterminal repeats, TTAA target site and an open reading frame encoding transposase with 68% similarity to IFP2. Vectorette PCR revealed large variation in the insertion sites of PgPLE1 amongst worldwide populations, indicating the potential mobility of PgPLE1. The PgPLE1 was undetectable in the genome of Pectinophora endema, implying the recent invasion of PgPLE1 after the divergence of these two closely related species.

Flame synthesis and in vitro biocompatibility assessment of superparamagnetic iron oxide nanoparticles: cellular uptake, toxicity and proliferation studies

Superparamagnetic iron oxide nanoparticles are used in diverse applications, such as targeted drug delivery, magnetic resonance imaging and hyperthermic malignant cell therapy. In the current work, superparamagnetic iron oxide nanoparticles were produced by flame synthesis, which has improved nanoparticle property control and is capable of commercial production rates with minimal post-processing. The iron oxide nanoparticle material characteristics were analyzed by electron microscopy and Raman spectroscopy. Finally, flame synthesized iron oxide nanoparticle interaction with endothelial cells was compared to commercially available iron oxide nanoparticles. Flame synthesis produced a heterogeneous mixture of 6-12 nm diameter hematite and magnetite nanoparticles with superparamagnetic properties. Endothelial cell scanning electron microscopy, confirmed by energy dispersive spectroscopy, demonstrated that flame synthesized nanoparticles are ingested into cells in a similar manner to commercially available nanoparticles. The flame synthesized particles showed no statistically significant toxicity difference from commercially available nanoparticles, as measured by Live/Dead assay, Alamar blue, and lactase dehydrogenase release. Neither type of nanoparticle affected cell proliferation induced by fibroblast growth factor-2. These data suggest that combustion synthesized iron oxide nanoparticles are comparable to commercially available nanoparticles for biological applications, yet flame synthesis is a simpler process with higher purity products and lower manufacturing costs. Future work will include functionalizing nanoparticles for specific cell targeting and bioactive factor delivery.

piggyBac-like elements in cotton bollworm, Helicoverpa armigera (Hübner)

Two piggyBac-like elements (PLEs) were identified in the cotton bollworm, Helicoverpa armigera, and were designated as HaPLE1 and HaPLE2. HaPLE1 is flanked by 16 bp inverted terminal repeats (ITRs) and the duplicated TTAA tetranucleotide, and contains an open reading frame (ORF) of 1794 bp with the presumed DDD domain, indicating that this element may be an active autonomously mobile element. HaPLE2 was found with the same ITRs, but lacks the majority of an ORF-encoding transposase. Thus, this element was thought to be a non-autonomous element. Transposable element displays and distribution of the two PLEs in individuals from three different H. armigera populations suggest that transmobilization of HaPLE2 by the transposase of HaPLE1 may be likely, and mobilization of HaPLE1 might occur not only within the same individual, but also among different individuals. In addition, horizontal transfer was probably involved in the evolution of PLEs between H. armigera and Trichoplusia ni.

Intact mariner-like element in tobacco budworm, Heliothis virescens (Lepidoptera: Noctuidae)

An intact mariner-like element was isolated from the genome of tobacco budworm, Heliothis virescens. This is the first report of an intact mariner element after the initial identification of Mos1 from Drosophila mauritiana. The full-length Hvmar1 has 30 bp inverted terminal repeats and a complete 1065 bp open reading frame (ORF) encoding the transposase with a 'D,D(34)D' motif in the catalytic domain. Polymerase chain reaction results show that at least one insertion of the Hvmar1 element is conserved in this Heliothis strain. Phylogenetic analysis demonstrated that Hvmar1 belongs to the irritans subfamily.

piggyBac-like elements in the tobacco budworm, Heliothis virescens (Fabricius)

We identified two different groups of piggyBac-like elements (PLE) in the tobacco budworm, Heliothis virescens, and named them HvPLE1 and HvPLE2. An intact copy of HvPLE1 revealed the characteristics of PLE: inverted terminal repeats, inverted subterminal repeats, and an open reading frame encoding transposase, whereas other HvPLE1 copies and all the HvPLE2 copies carried disruptive mutations in the region encoding transposase. We also identified none to two bands per genome hybridized to a probe of Trichoplusia ni piggyBac in genomic Southern blotting, which are different from HvPLE1 or HvPLE2. Analysis of the sequences of multiple copies of HvPLE1 and HvPLE2 suggests that the PLEs are closely related to the T. ni piggyBac, of relatively young age, and independently entered the H. virescens genome.

In vitro activities of antibiotics and antimicrobial peptides against the plant pathogenic bacterium Xylella fastidiosa

AIMS

The objective of this study was to evaluate the effectiveness of antibiotics and antimicrobial peptides against 10 strains of Xylella fastidiosa.

METHODS AND RESULTS

The minimal inhibitory concentration (MIC) of 12 antibiotics and 18 antimicrobial peptides were determined by agar dilution tests and growth inhibition assays. Antibiotics with the lowest MIC for X. fastidiosa strains were gentamicin, tetracycline, ampicillin, kanamycin, and novobiocin, chloramphenicol, and rifampin. Plate growth inhibition assays showed that four of the antimicrobial peptides (Magainin 2, Indolicidin, PGQ, and Dermaseptin) were toxic to all X. fastidiosa strains.

CONCLUSION

All X. fastidiosa strains were sensitive to several groups of antibiotics, and minor differences in sensitivity to several antimicrobial peptides were observed among strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows that antibiotics and antimicrobial peptides have some activity against the pathogen, X. fastidiosa and may have application in protecting plants from developing Pierce's disease.

Hypericum perforatum L. extract – Novel photosensitizer against human bladder cancer cells

The polar methanolic fraction (PMF) of the Hypericum perforatum L. extract has recently been developed and tested as a novel, natural photosensitizer for use in the photodynamic therapy (PDT), and photodynamic diagnosis (PDD). PMF has been tested on HL-60 leukemic cells and cord blood hemopoietic progenitors. In the present study, the efficacy of PMF as a phototoxic agent against urinary bladder carcinoma has been studied using the T24 (high grade metastatic cancer), and RT4 (primary low grade papillary transitional cell carcinoma) human bladder cancer cells. Following cell culture incubation, PMF was excited using 630 nm laser light. The photosensitizer exhibited significant photocytotoxicity in both cell lines at a concentration of 60microg/ml, with 4-8 J/cm(2) light dose, resulting in cell destruction from 80% to 86%. At the concentration of 20microg/ml PMF was not active in either cell line. These results were compared with the results obtained in the same cell lines, under the same conditions with a clinically approved photosensitizer, Photofrin. Photofrin was used in the maximum clinically tolerable dose of 4microg/ml, and it was also excited with 630 nm laser light. In the T24 cell Photofrin exhibited slightly less photocytotocixity, compared with PMF, resulting in 77% cell death with 8J/cm(2) light dose. However, against the RT4 cells Photofrin resulted in minimal cell death (9%) with even 8J/cm(2) light dose. Finally, the type of cell death induced by PMF photoactivation was studied using flow cytometry and DNA laddering. Cell death by PMF photodynamic action in these two bladder cell lines is caused predominently by apoptosis. The reported significant photocytotoxicity, selective localization, natural abundance, easy, and inexpensive preparation, underscore that the PMF extract hold the promise of being a novel, effective PDT photosensitizer.

Inactivated mariner-like elements (MLE) in pink bollworm, Pectinophora gossypiella

We isolated multiple copies of mariner-like element (MLE) from the pink bollworm (PBW), Pectinophora gossypiella, a key lepidopteran cotton pest. Although all the MLE sequences contain multiple mutations accumulated in their transposase coding region, the consensus sequence revealed a putative ancestral transposase encoding 339 amino acid residues with a D,D(34)D motif, and 36 bp inverted terminal repeats, belonging to the cecropia subfamily, and most similar to the MLE found in Antheraea species. Examining six different pink bollworm populations, we conclude that the MLE in PBW described in this study are ancient and are undergoing the process of accumulating inactivating mutations. This conclusion is supported by the patterns of polymorphisms revealed by genomic Southern hybridization, transposable element displays, and sequences from multiple MLE.

Mechanisms of resistance to pyrethroid insecticides

In the 10 years or so since the photostable pyrethroid insecticides such as permethrin and fenvolerate were introduced, this family of compounds has become widely used to control agricultural pests, and finds increasing usage to control arthropods of medical and veterinary importance. The synthetic pyrethroids offer many advantages for veterinary and public health use, particularly their selectivity, high toxicity to insects, and relative lack of chronic effects. They are also inherently stable, and so have become widely used as residual sprays on house walls to control insects in the domestic environment. But as with other classes of insecticides such as organochlorines, organophosphotes and carbamates, resistance to pyrethroids is now increasingly reported. In this article, Tom Miller explains the principle mechanisms of resistance to pyrethroids, using the North American horn fly (Haematobia irritans) as an example now showing many common resistance traits.

Impact of pymetrozine on glassy-winged sharpshooter feeding behavior and rate of Xylella fastidiosa transmission

Pymetrozine is a compound that interferes with insect feeding and interrupts transmission of plant pathogens. The glassy-winged sharpshooter, Homalodisca coagulata Say (Hemiptera, Cicadellidae), is a vector of Xylella fastidiosa, the foregut-borne, propagative bacterium that causes Pierce's disease of grapevine. In this study, we recorded the behavioral response of H. coagulata to plants treated by soil drench with pymetrozine using time-lapse photography, quantified the reduction in liquid excreta produced by H. coagulata fed on pymetrozine-treated plants, and evaluated pymetrozine effectiveness in reducing transmission rate in grapevines. H. coagulata feeding on plants treated with 0.015 mg of pymetrozine was disrupted by decreasing the number of contacts made with the grapevine by more than 50% and by increasing movements away from the stem by more than 5-fold. Excreta production by H. coagulata was significantly reduced on plants treated with 0.015 or 0.0075 mg of pymetrozine. Contrary to the expected outcome, the mean number of X. fastidiosa-infected plants actually increased in the pymetrozine treatments relative to the controls.

Evaluation of methods for extracting Xylella fastidiosa DNA from the glassy-winged sharpshooter

The recent spread of the plant pathogenic bacterium Xylclla fastidiosa Wells et al. by an invasive vector species, Homalodisca coagulata Say, in southern California has resulted in new epidemics of Pierce's disease of grapevine. Our goal is to develop an efficient method to detect low titers of X. fastidiosa in H. coagulata that is amenable to large sample sizes for epidemiological studies. Detection of the plant pathogenic bacterium X. fastidiosa in its insect vector is complicated by low titers of bacteria, difficulty in releasing it from the insect mouthparts and foregut, and the presence of substances in the insect that inhibit polymerase chain reaction (PCr). To select the optimal protocol for DNA extraction to be used with PCR, we compared three standard methods and 11 commercially available kits for relative efficiency of X. fastidiosa DNA extraction in the presence of insect tissue. All of the protocols tested were proficient at extracting DNA from pure bacterial culture (1 x 10(5) cells), and all but one protocol successfully extracted sufficient bacterial DNA in the presence of insect tissue. Three DNA extraction techniques, immunomagnetic separation, the DNeasy Tissue kit (Qiagen, Hercules, CA), and Genomic DNA Purification kit (Fermentus, Hanover, MD), were compared more closely using a dilution series of X. fastidiosa (5000-0 cells) with and without insect tissue present. The DNeasy Tissue kit was the best kit tested, allowing detection of 5 x 10(3) X. fastidiosa cells with an insect head background.

A simplified method for studying hypoxia and reoxygenation injury under in vitro conditions

A hypoxia chamber was constructed which allowed for the sequential sampling and blood gas analysis of buffer bathing cells in culture which were subjected to graded periods of hypoxia. Following hypoxia, the human fetal small intestinal cells (CCL-241) were placed into a normoxic environment for the remainder of a 24 h study period. A cytotoxicity assay revealed significant mortality in cells subjected to hypoxia and reoxygenation, but not in those subjected to hypoxia alone. Analysis of lactate dehydrogenase release into buffer samples also indicated a greater cellular injury among cells exposed to hypoxia and reoxygenation. Additionally, levels of lipid peroxidation products were found to be significantly elevated in cells exposed to periods of hypoxia followed by reoxygenation, but not hypoxia alone, as measured by a thiobarbituric acid fluorometric assay. This suggests that lipid peroxidation mediated by oxygen-derived free radical species is the mechanism of injury in these cells. This study demonstrates that such a chamber provides a more precise way to monitor hypoxia and is a useful tool for studying hypoxia and reoxygenation under in vitro conditions.

Role of calcium homeostasis in gastric mucosal injury and protection

Using a human gastric mucosal cell line, known as AGS cells, we determined the role that perturbations in intracellular Ca2+ concentration [Ca2+]i might play in cellular injury induced by various damaging agents. For deoxycholate (CD) and ethanol (EtOH) induced damage, a concentration related increase in [Ca2+]i was noted that preceded and closely paralleled the magnitude of injury. Thus, the higher the concentration of DC or EtOH, the more profound were the changes in [Ca2+]i and the resultant degree of cellular injury. Pretreatment with a low concentration of DC (50 microM; called a mild irritant) that was not damaging by itself attenuated injury induced by a damaging concentration (i.e. 250 microM) of DC, and appeared to elicit this protective action through mechanisms that resisted intracellular Ca2+ accumulation. Additional studies indicated that the mechanism of aspirin damage may be similar and that other protective agents such as prostaglandins and growth factors appear to mediate their protective properties through prevention of intracellular Ca2+ alterations. We propose that agents that prevent mucosal injury mediate this activity through a cellular response (involving active Ca2+ efflux) that subsequently provides a protective action by limiting the magnitude of intracellular Ca2+ accumulation.

Hindlimb unloading induces a collagen isoform shift in the soleus muscle of the rat

To determine whether hindlimb unloading (HU) alters the extracellular matrix of skeletal muscle, male Sprague-Dawley rats were subjected to 0 (n = 11), 1 (n = 11), 14 (n = 13), or 28 (n = 11) days of unloading. Remodeling of the soleus and plantaris muscles was examined biochemically for collagen abundance via measurement of hydroxyproline, and the percentage of cross-sectional area of collagen was determined histologically with picrosirius red staining. Total hydroxyproline content in the soleus and plantaris muscles was unaltered by HU at any time point. However, the relative proportions of type I collagen in the soleus muscle decreased relative to control (Con) with 14 and 28 days HU (Con 68 +/- 5%; 14 days HU 53 +/- 4%; 28 days HU 53 +/- 7%). Correspondingly, type III collagen increased in soleus muscle with 14 and 28 days HU (Con 32 +/- 5%; 14 days HU 47 +/- 4%; 28 days HU 48 +/- 7%). The proportion of type I muscle fibers in soleus muscle was diminished with HU (Con 96 +/- 2%; 14 days HU 86 +/- 1%; 28 days HU 83 +/- 1%), and the proportion of hybrid type I/IIB fibers increased (Con 0%; 14 days HU 8 +/- 2%; 28 days HU 14 +/- 2%). HU had no effect on the proportion of type I and III collagen or muscle fiber composition in plantaris muscle. The data demonstrate that HU induces a shift in the relative proportion of collagen isoform (type I to III) in the antigravity soleus muscle, which occurs concomitantly with a slow-to-fast myofiber transformation.

Gastric surgery

Significant advances in the role of gastric surgery in the management of disease in the past year have focused on three broad areas: morbid obesity, gastric cancer, and peptic ulcer disease. Although vertical banded gastroplasty and Roux-en-Y gastric bypass are the two procedures most commonly used in the United States to induce weight loss in the morbidly obese patient, long-term follow-up continues to support the durability of the gastric bypass in maintaining a sustainable outcome with a minimum of complications. It is not surprising, therefore, that increasing interest has accrued in simplifying this operation and decreasing potential complications even further by employing laparoscopic technology. In the area of gastric cancer, several reports have provided important new information regarding its pathogenesis, factors influencing long-term survival, and strategies for management when diagnosed early. Finally, in patients developing the complications of peptic ulcer disease (eg, obstruction and perforation), conservative management has been emphasized over more radical traditional approaches. This review highlights these advances.

Effect of short-term microgravity and long-term hindlimb unloading on rat cardiac mass and function

The purpose of this study was to test the hypothesis that exposure to short-term microgravity or long-term hindlimb unloading induces cardiac atrophy in male Sprague-Dawley rats. For the microgravity study, rats were subdivided into four groups: preflight (PF, n = 12); flight (Fl, n = 7); flight cage simulation (Sim, n = 6), and vivarium control (Viv, n = 7). Animals in the Fl group were exposed to 7 days of microgravity during the Spacelab 3 mission. Animals in the hindlimb-unloading study were subdivided into three groups: control (Con, n = 20), 7-day hindlimb-unloaded (7HU, n = 10), and 28-day hindlimb-unloaded (28HU, n = 19). Heart mass was unchanged in adult animals exposed to 7 days of actual microgravity (PF 1.33 +/- 0.03 g; Fl 1.32 +/- 0.02 g; Sim 1.28 +/- 0.04 g; Viv 1.35 +/- 0.04 g). Similarly, heart mass was unaltered with hindlimb unloading (Con 1.40 +/- 0.04 g; 7HU 1.35 +/- 0.06 g; 28HU 1.42 +/- 0.03 g). Hindlimb unloading also had no effect on the peak rate of rise in left ventricular pressure, an estimate of myocardial contractility (Con 8,055 +/- 385 mmHg/s; 28HU 8,545 +/- 755 mmHg/s). These data suggest that cardiac atrophy does not occur after short-term exposure to microgravity and that neither short- nor long-term simulated microgravity alters cardiac mass or function.

Isolation and identification of bacteria associated with adult laboratory Mexican fruit flies, Anastrepha ludens (Diptera: Tephritidae)

From the guts of new and old colonies (female and male) of Mexican fruit flies, Anastrepha ludens (Diptera: Tephritidae), we identified a total of 18 different bacterial species belonging to the family Enterobacteriaceae, Pseudomonadaceae, Vibrionaceae, Micrococcaceae, Deinococcacea, Bacillaceae, and the genus Listeria. Enterobacter, Providencia, Serratia, and Staphylococcus spp. were the most frequently isolated genera, with Citrobacter, Streptococcus, Aerococcus, and Listeria found less frequently. We found Bacillus cereus, Enterobacter sakazakii, Providencia stuartii, and Pseudomonas aeruginosa only in the new colony, Aeromonas hydrophila and Klebsiella pneumoniae spp. pneumoniae only in the old colony. We also studied resistance/sensitivity to 12 antibiotics for six bacterial isolates such as Enterobacter cloacae, E. sakazakii, K. pneumoniae spp., Providencia rettgeri, P. aeruginosa, and Bacillus cereus. Isolates on the whole were resistant to penicillin and ampicillin (five of six isolates) and sensitive to rifampin and streptomycin (six of six isolates). Antibiotic resistance profiles might be useful characteristics for distinguishing among species and strains of these bacteria, probably having ecological significance with respect to intra- and inter-specific competition within host cadavers, and could have implications for the utility of these organisms for biological control, including the alternative control strategy, paratransgenesis.

Visual function is stable in patients who continue long-term vigabatrin therapy: implications for clinical decision making

PURPOSE

Vigabatrin (VGB) has been shown to cause visual field constriction and other forms of mild visual dysfunction. We determined the safety of continuing VGB therapy in patients who had received prolonged treatment (>2 years) with the drug by serially monitoring changes in visual function over a 1-year period of continued therapy. We also followed up patients who discontinued VGB to see whether alternative therapies are effective.

METHODS

Fifteen of 17 patients who continued VGB therapy had visual-function testing (visual acuity, color vision, kinetic and static perimetry) every 3 months for 1 year. Eighteen patients who discontinued VGB were given alternative antiepileptic drugs (AEDs); their seizure responses were measured after > or =3 months of treatment.

RESULTS

Patients continuing VGB showed no worsening of visual acuity, color vision, or visual-field constriction beyond that measured in the initial test. Many patients who discontinued VGB had good seizure control with either newer or previously unsuccessful AEDs.

CONCLUSIONS

For patients who have an excellent response to VGB and only mild visual changes, continued therapy may be safe with close visual monitoring. Patients who do not have a significant reduction in seizures or who experience considerable visual dysfunction with VGB may respond well to alternative therapies.

Effect of serial passage on gene expression in MC3T3-E1 preosteoblastic cells: a microarray study

The osteoblastic function of mouse preosteoblastic MC3T3-E1 cells, as measured by alkaline phosphatase activity and osteocalcin secretion, decreases after serial passage. To uncover genes responsible for decreased osteoblastic function in high-passage cells, we have studied passage-dependent change of gene expression in MC3T3-E1 cells. Changes in the expression pattern of 2000 selected genes were examined simultaneously by comparing mRNA levels between MC3T3-E1 cells at passage 20 and passage 60 using the cDNA microarray analysis. Significant changes in the steady-state abundance of 27 mRNAs were observed in response to different passage numbers, including 17 known genes, 4 ESTs with homology to known genes, and 6 genes with no previously described function or homology. Northern blot analysis was used to verify and quantify the expression of selected genes, and revealed a significant higher level of up- and down-regulation compared to microarray data. These results indicate the existence of a significant change in gene expression in osteoblastic cells undergoing serial passages. Such changes might be responsible for a reduction in bone regeneration in older osteoblasts. Potential roles of selected genes in bone aging are discussed.

Wartenberg's migrant sensory neuritis

We describe a patient with the sudden onset of a painful, purely sensory, mononeuritis multiplex. Investigations showed no evidence for any underlying systemic condition. A nerve biopsy showed fascicular wallerian degeneration with perineurial thickening, inflammatory cells, and immunoglobulin G (IgG) deposition. His painful sensory deficits persisted, with no improvement after treatment with prednisone. The clinical characteristics in this case were very similar to those originally described by Wartenberg, and subsequently by other investigators. The investigations in our case strongly suggest that there may be an underlying immune pathogenesis for cases of Wartenberg's migrant sensory neuritis.

Diagnosis of prostate adenocarcinoma using transurethral resection of the prostate after multiple negative transrectal biopsies and persistently elevated prostate-specific antigen level

We report a case of prostate cancer diagnosis by transurethral resection of the prostate in a man who underwent more than 50 needle biopsies by three different physicians for an increasing prostate-specific antigen level. Radical prostatectomy resulted in removal of an organ-confined tumor (T2aN0M0), and a short follow-up revealed an undetectable prostate-specific antigen level.

Cytoskeleton as a target for injury in damaged intestinal epithelium

This report summarizes the findings of a series of studies undertaken to discern the role of the cytoskeleton in intestinal injury and defense. Two established cell lines were used for these studies. IEC-6 cells (a rat intestinal cell line) were incubated in Eagle's minimal essential medium with and without 16, 16 dimethyl prostaglandin E(2) (dmPGE(2); 2.6 microM) for 15 minutes and subsequently incubated in medium containing 10% ethanol (EtOH). The effects on cell viability and the actin cytoskeleton were then determined. Using a similar protocol, Caco-2 cells (a human colonic cell line) were employed to assess the microtubule cytoskeleton under these conditions. In both cell lines, EtOH extensively disrupted the cytoskeletal component being evaluated coincident with adversely affecting cell viability. Pretreatment with dmPGE(2) increased cell viability and abolished the disruptive effects on both the actin and microtubule cytoskeleton in cells exposed to EtOH. Prior incubation with cytochalasin D, an actin disruptive agent, prevented the protective capabilities of dmPGE(2) in IEC-6 cells challenged with EtOH. Phalloidin, an actin stabilizing agent, demonstrated similar effects to that of dmPGE(2) by stabilizing the actin cytoskeleton and preserving cellular viability in IEC-6 cells in response to EtOH. In Caco-2 cells, taxol, a microtubule stabilizing agent, mimicked the effects of dmPGE(2) by increasing cell viability in cells exposed to EtOH and enhancing microtubular integrity. In contrast, pretreatment with colchicine, an inhibitor of microtubule integrity, prevented the protective effects of dmPGE(2). These findings support the hypothesis that the cytoskeleton may be a major target for injury in damaged intestinal epithelium, and that the protective action of dmPGE(2) is orchestrated through preservation of this target.

Cytoskeleton as a target for injury in damaged intestinal epithelium

This report summarizes the findings of a series of studies undertaken to discern the role of the cytoskeleton in intestinal injury and defense. Two established cell lines were used for these studies. IEC-6 cells (a rat intestinal cell line) were incubated in Eagle's minimal essential medium with and without 16, 16 dimethyl prostaglandin E(2) (dmPGE(2); 2.6 microM) for 15 minutes and subsequently incubated in medium containing 10% ethanol (EtOH). The effects on cell viability and the actin cytoskeleton were then determined. Using a similar protocol, Caco-2 cells (a human colonic cell line) were employed to assess the microtubule cytoskeleton under these conditions. In both cell lines, EtOH extensively disrupted the cytoskeletal component being evaluated coincident with adversely affecting cell viability. Pretreatment with dmPGE(2) increased cell viability and abolished the disruptive effects on both the actin and microtubule cytoskeleton in cells exposed to EtOH. Prior incubation with cytochalasin D, an actin disruptive agent, prevented the protective capabilities of dmPGE(2) in IEC-6 cells challenged with EtOH. Phalloidin, an actin stabilizing agent, demonstrated similar effects to that of dmPGE(2) by stabilizing the actin cytoskeleton and preserving cellular viability in IEC-6 cells in response to EtOH. In Caco-2 cells, taxol, a microtubule stabilizing agent, mimicked the effects of dmPGE(2) by increasing cell viability in cells exposed to EtOH and enhancing microtubular integrity. In contrast, pretreatment with colchicine, an inhibitor of microtubule integrity, prevented the protective effects of dmPGE(2). These findings support the hypothesis that the cytoskeleton may be a major target for injury in damaged intestinal epithelium, and that the protective action of dmPGE(2) is orchestrated through preservation of this target.

5-HETE congeners as modulators of cell proliferation

The synthesis and assessment of the mitogenic properties of 5-HETE congeners are reported. These studies represent an effort to develop a structure-activity profile for ligands of the 5-HETE/5-oxoETE G-protein coupled receptor(s). Many of these agents possess mitogenic activity that equals or exceeds that of racemic 5-HETE family constituents in prostate cancer cell lines.

A mechanistic approach to understanding species differences in felbamate bioactivation: relevance to drug-induced idiosyncratic reactions

In an attempt to understand the species-selective toxicity of felbamate (2-phenyl-1,3-propanediol dicarbamate, FBM), which is thought to result from bioactivation to 2-phenylpropenal, FBM metabolism was evaluated in rats and humans. The formation of 2-phenylpropenal was monitored by the amount of its mercapturates excreted in urine. The data show a relative 5-fold increase in mercapturate excretion in patient urine as a result of differences in metabolism through P450-, esterase-, and aldehyde dehydrogenase-mediated pathways. To compensate for the significant species differences in FBM metabolism, and to produce toxic levels of 2-phenylpropenal in rat comparable to humans levels, monocarbamate felbamate (2-phenyl-1,3-propanediol monocarbamate, MCF), was administered to rats in the hopes of eliciting a toxic response. The desired result, an increase in mercapturate excretion, was not observed in MCF-treated rats due to the identification of a new FBM metabolite, 2-phenyl-1,3-propanediol monocarbamate-alpha-D-glucuronic acid (MCF-glucuronide). Formation of MCF-glucuronide is significant and represents about 80% of MCF metabolites in MCF-dosed rats, 3% of FBM metabolites in FBM-dosed rats, and about 11% of FBM metabolites in FBM patients. To overcome the protective effect of glucuronidation, uridine diphosphoglucuronosyltransferase (UGT)-deficient Gunn rats were treated with FBM and MCF, which surprisingly had no effect on the amount of MCF-glucuronide formed. Given the known UGT polymorphisms and the fact that MCF glucuronidation contributes to the elimination of a 2-phenylpropenal precursor, the correlation between poor UGT activity and an increase in mercapturates excretion was evaluated in patients. The result of the first 34 patients screened suggests that a patient with poor UGT activity is not necessarily at risk for FBM toxicity.

Transformation of internal extracellular bacteria isolated from Rhagoletis completa cresson gut with enhanced green fluorescent protein

We discovered Zeocintrade mark is an effective antibiotic against Enterobacter agglomerans and Klebsiella pneumoniae strains isolated from the walnut husk fly (Rhagoletis completa Cresson: Family Tephritidae) and that bleomycin resistance can be used as a selective marker in transforming plasmids. We transformed Ent. agglomerans and K. pneumoniae strains originally isolated from their close association with R. completa gut to produce enhanced green fluorescent protein, a variant of green fluorescent protein in the first demonstration of genetic transformation of internal extracellular bacteria isolated from a tephritid pest. We report methods for plasmid-mediated transformation of these bacteria, the expression of fluorescent marker protein from the transforming plasmids, and the stability of the transforming plasmid in the bacteria. We also discuss applications of this technology in the study of pest biology and control implementation.

Germ-line transformation of pink bollworm (Lepidoptera: gelechiidae) mediated by the piggyBac transposable element

The pink bollworm, Pectinophora gossypiella, is a world-wide pest of cultivated cotton. In certain growing regions populations are suppressed by a sterile release strategy. Efforts to improve the sterile insect technique as well as our understanding of lepidopteran biology could benefit greatly from a germ-line transformation system. We report transformation of pink bollworm with a piggyBac transposable element carrying the enhanced green flourescent protein (EGFP) marker gene. This vector-marker system resulted in recovery of transgenics at a rate of approximately 3.5%. Integration of the transforming construct that was typical of piggyBac was demonstrated by Southern analysis and sequence determination of transposon flanks. Expression of the EGFP marker was visualized by fluorescent microscopy and Western Blot analysis. Maintenance of transformed strains indicates that the transgene segregates in a Mendelian fashion and has been stable over fourteen generations to date.

The synthesis, in vitro reactivity, and evidence for formation in humans of 5-phenyl-1,3-oxazinane-2,4-dione, a metabolite of felbamate

Previously we have proposed and provided evidence for a metabolic scheme leading to 3-carbamoyl-2-phenylpropionaldehyde from the antiepileptic drug felbamate. This aldehyde was found to undergo reversible cyclization to form the more stable cyclic carbamate 4-hydroxy-5-phenyl-tetrahydro-1,3-oxazin-2-one or undergo elimination to form 2-phenylpropenal. The cyclic carbamate bears structural similarity to 4-hydroxycyclophosphamide and there is an intriguing parallelism between the pathway from the cyclic carbamate to 2-phenylpropenal and the known pathway from 4-hydroxycyclophosphamide to acrolein. The similarity of these transformations led us to consider 5-phenyl-1,3-oxazinane-2,4-dione, which could arise from an oxidation of the cyclic carbamate, as a potential metabolite of felbamate. As the formation of this dione species may have both potential pharmacologic and toxicologic implications for felbamate therapy, we wished to study its reactivity. We have developed a synthesis of 5-phenyl-1, 3-oxazinane-2,4-dione and evaluated its reactivity in vitro. This dione was found to undergo base-catalyzed decomposition to three products, one of which is the major human metabolite of felbamate, 3-carbamoyl-2-phenylpropionic acid. Furthermore, we have found evidence for the presence of the dione in human urine after felbamate treatment through the identification of its major in vitro decomposition product, 2-phenylacrylamide 11.

Lateral subcutaneous brow lift and interbrow muscle resection: clinical experience and anatomic studies

The authors report consistent improvement in 65 patients with lateral brow ptosis by using a lateral subcutaneous brow lift at the temporal hairline. In 48 of these patients, vertical glabellar wrinkles were improved by the direct excision of procerus, corrugator, and orbicularis muscles through 3-mm medial brow incisions. Anatomic dissections in 10 cadavers and examinations of 50 skulls were used to study the location of the supraorbital and supratrochlear nerves. Dissections revealed that the supratrochlear nerve was never closer than 1.6 cm to the midline at the level of the supraorbital ridge. In no dissection was a supratrochlear foramen noted. Lateral subcutaneous brow lift was consistently successful in elevating the lateral brow. In no patient was nerve damage to the supraorbital nerve noted. In most patients, the temporal hairline was improved by excising a triangle of balding scalp. Through 3-mm medial brow incisions, the interbrow musculature can be excised by using a small rongeur in an area 3.2 cm wide without risk of nerve damage, improving vertical glabellar wrinkles.

Nonsteroidal anti-inflammatory drugs attenuate proliferation of colonic carcinoma cells by blocking epidermal growth factor-induced Ca++ mobilization

Numerous studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit colorectal carcinogenesis. We have previously reported that NSAIDs, in human colonic carcinoma cells (Caco-2), attenuate epidermal growth factor (EGF)-induced cellular proliferation through a process independent of their inhibitory effects on prostaglandin synthesis. Furthermore, separate studies have also suggested that NSAIDs inhibit EGF-induced store-operated Ca++ influx. Thus we developed the hypothesis that NSAIDs may limit the activity of EGF by altering intracellular Ca++ ([Ca++]i) mobilization. Serum-deprived Caco-2 cells were employed for all experimentation. [Ca++]i was measured with Fluo-3 and extracellular Ca++ influx was monitored by quenching Fluo-3 fluorescence with Mn++. Proliferation was quantitated with two assays: cellular nucleic acid and total protein content. Caco-2 cells exposed to EGF demonstrated an initial increase in [Ca++]i which was blocked by neomycin, an inhibitor of IPsubscript 3 generation, and the phospholipase C inhibitor U73122 but not U73343 (inactive control). This was followed by sustained extracellular Ca++ influx, which was attenuated with calcium-free buffer (-Ca++), the store- operated Ca++ channel blocker lanthanum, indomethacin, ibuprofen, and aspirin. In subsequent studies, cells were treated with either serum-free media or EGF +/- the aforementioned inhibitors, and again serum starved. Cells exposed to EGF +/- the inactive phospholipase C inhibitor U73343 demonstrated a significant increase in nucleic acid and protein. However, proliferation induced by EGF was not observed when [Ca++]i elevation was prevented by blocking either internal Ca++ store release via phospholipase C/IPsubscript 3 or sustained Ca++ influx through store-operated Ca++ channels. Sustained [Ca++]i elevation, as induced by EGF, appears to be required for mitogenesis. These data support our premise that one mechanism whereby NSAIDs may attenuate colonic neoplasia is by blocking EGF-induced Ca++ mobilization.

Epidermal growth factor-induced cytoprotection in human intestinal cells involves intracellular calcium signaling

BACKGROUND

The mechanism(s) whereby epidermal growth factor (EGF) protects against cellular injury remains poorly understood. Previous data in our laboratory have suggested that EGF-induced cellular proliferation in human colonic carcinoma cells (Caco-2) may involve changes in intracellular calcium content ([Ca(2+)](i)). Our current objective was to determine if a similar process was involved with EGF-induced cytoprotection.

METHODS

Postconfluent Caco-2 cells were employed for all experimentation. [Ca(2+)](i) was measured with Fluo-3 fluorescence. Injury was measured employing Ethidium homodimer 1 uptake and lactate dehydrogenase (LDH) release.

RESULTS

Caco-2 cells pretreated, but not concomitantly treated, with EGF (10-100 ng/ml, 30-60 min) significantly attenuated cellular injury induced subsequently by 500 microM deoxycholate (DC). Cells exposed to 100 ng/ml EGF demonstrated an initial increase in [Ca(2+)](i) (1-5 min) which was blocked with neomycin, an inhibitor of inositol 1,4,5-trisphosphate (IP(3)) generation, and the phospholipase C (PLC) inhibitor U73122, but not U73343 (inactive control). This was followed by sustained extracellular Ca(2+) influx (5-20 min), which was attenuated with calcium-free buffer and the store operated Ca(2+) channel blocker La(3+). [Ca(2+)](i) then returned to baseline (20-30 min), a process blocked with the Ca(2+)-ATPase inhibitors quercetin and vanadate. The above treatments, which in and of themselves did not induce cellular injury, were repeated and cells were subsequently exposed to DC. All groups exposed to 500 microM DC demonstrated significant increases in both Ethidium Homodimer 1 uptake and LDH release. Both indices of injury were significantly decreased when cells were pretreated with EGF +/- the inactive PLC inhibitor U73343. However, protection induced by EGF was lost when any of its effects on changes in [Ca(2+)](i) were prevented: internal Ca(2+) store release via PLC and IP(3), sustained Ca(2+) influx through store operated Ca(2+) channels, or subsequent Ca(2+) efflux.

CONCLUSION

Taken together, these data strongly suggest that the cytoprotective effects of EGF may involve Ca(2+) signaling.

Role of actin cytoskeleton in prostaglandin-induced protection against ethanol in an intestinal epithelial cell line

Prostaglandins (PGs) protect a variety of gastrointestinal cells against injury induced by ethanol and other noxious agents. This investigation attempted to discern the mechanism of cytoprotection as it relates to the relationship between actin and PGs in IEC-6 cells (a rat intestinal epithelial cell line). IEC-6 cells were incubated in Dulbecco's modified Eagle's medium +/- 16,16-dimethyl prostaglandin E(2) (dmPG, 2.6 microM) for 15 min and subsequently incubated in medium containing 1, 2.5, 5, 7.5, and 10% ethanol (EtOH). Cells were then processed for immunocytochemistry using FITC-phalloidin in order to stain the actin cytoskeleton, and cell viability was determined by trypan blue exclusion. Quantitative Western immunoblotting of fractioned G-actin (nonpolymerized; S1) and F-actin (polymerized; S2) was also carried out. EtOH concentrations equal to and greater than 5% led to the collapse of the actin cytoskeleton as depicted by extensive disorganization and fragmentation. In addition, these same EtOH concentrations significantly decreased the S2 fraction and increased the S1 pool of actin. Preincubation with dmPG prevented collapse of the actin cytoskeleton, significantly increased the S2 polymerized fraction as determined by quantitative immunoblotting, and increased cell viability in EtOH-treated cultures. Prior incubation with cytochalasin D, an actin disruptive agent, not only reduced cell viability but also prevented the cytoprotective effects of dmPG. Phalloidin, an actin stabilizing agent, had effects similar to that of dmPG as demonstrated by stability of the actin cytoskeleton and increased cellular viability. Such findings indicate that PGs are important in the organization and stability of actin under in vitro conditions. These effects on actin may play an essential role in the mechanism of PG-induced cytoprotection.

Diagnostic evaluation of erectile dysfunction

Erectile dysfunction, the persistent inability to attain or maintain penile erection sufficient for sexual intercourse, affects millions of men to various degrees. The majority of cases have an organic etiology, most commonly vascular disease that decreases blood flow into the penis. Regardless of the primary cause, erectile dysfunction can have a negative impact on self-esteem, quality of life and interpersonal relationships. The initial step in evaluation is a detailed medical and social history, including a review of medication use. Discussion with the patient's sexual partner may clarify exacerbating issues. The physical examination focuses on the cardiovascular, neurologic and urogenital systems. Laboratory tests are useful to screen for common etiologic factors and, when indicated, to identify hypogonadal syndromes. Appropriate evaluation of erectile dysfunction leads to accurate advice, management and referral of patients with erectile dysfunction.

A state-wide evaluation of appendectomy in children

BACKGROUND

Traditional management of appendicitis in children involves open appendectomy (OA), an operation that is relatively inexpensive and carries few risks and complications. However, little information is available regarding the use, cost, and complication of laparoscopic appendectomy (LA) in children.

METHODS

Our initial aim was to determine if LA is frequently performed in children (<15 years). We then compared the surgical results of OA versus LA. In conjunction with the Missouri Department of Health, we evaluated 793 children treated for appendicitis throughout the state between January 1997 and June 1997. The authors were blinded to the patient, surgeon, and hospital; no children were excluded.

RESULTS

LA was infrequently performed in children with advanced disease. Overall, children undergoing LA were older and had a shorter hospitalization but no difference in hospital charge. When separated by child age, LA was associated with a shorter length of stay in all groups (0 to 5, 6 to 10, and 11 to 15 years) but only children in the 6 to 10 year range had a lower hospital charge when compared with patients undergoing OA.

CONCLUSIONS

LA is becoming a common surgical approach for older children with simple appendicitis. Furthermore, these data suggest that LA, independent of individual surgeon or medical center, is associated with a decreased length of hospitalization without a significant difference in hospital charge.

Serial passage of MC3T3-E1 cells alters osteoblastic function and responsiveness to transforming growth factor-beta1 and bone morphogenetic protein-2

The murine-derived clonal MC3T3-E1 cell is a well-studied osteoblast-like cell line. To understand the effects of serial passages on its cellular function, we examined changes in cell morphology, gap junctional intercellular communication (GJIC), proliferation, and osteoblastic function between early passage (<20) and late passage (>65) cells. MC3T3-E1 cells developed an elongated, spindle shape after multiple passages. Intercellular communication decreased significantly (33%) in late vs. early passage cells. Transforming growth factor-beta1 (TGF-beta1) stimulated cell proliferation in early passage cells and induced c-fos expression, while it inhibited proliferation in late passage cells. Using alkaline phosphatase (ALP) activity and osteocalcin (OC) secretion as markers for osteoblastic function and differentiation, we demonstrated that both markers were significantly reduced after multiple cell passages. Bone morphogenetic protein-2 (BMP-2) significantly enhanced ALP activity and OC secretion in early passage cells while TGF-beta1 exerted an opposite effect. Both BMP-2 and TGF-beta1 had minimal effects on late passage cells. We conclude that serial passage alters MC3T3-E1 cell morphology, and significantly diminishes GJIC, osteoblastic function, TGF-beta1-mediated cell proliferation, and responsiveness to TGF-beta1 and BMP-2. Cell passage numbers should be clearly defined in functional studies involving MC3T3-E1 cells.