Pathologic Lymph Node Regression After Neoadjuvant Chemotherapy Predicts Recurrence and Survival in Esophageal Adenocarcinoma: A Multicenter Study in the United Kingdom

PURPOSE

There is limited evidence regarding the prognostic effects of pathologic lymph node (LN) regression after neoadjuvant chemotherapy for esophageal adenocarcinoma, and a definition of LN response is lacking. This study aimed to evaluate how LN regression influences survival after surgery for esophageal adenocarcinoma.

METHODS

Multicenter cohort study of patients with esophageal adenocarcinoma treated with neoadjuvant chemotherapy followed by surgical resection at five high-volume centers in the United Kingdom. LNs retrieved at esophagectomy were examined for chemotherapy response and given a LN regression score (LNRS)-LNRS 1, complete response; 2, <10% residual tumor; 3, 10%-50% residual tumor; 4, >50% residual tumor; and 5, no response. Survival analysis was performed using Cox regression adjusting for confounders including primary tumor regression. The discriminatory ability of different LN response classifications to predict survival was evaluated using Akaike information criterion and Harrell C-index.

RESULTS

In total, 17,930 LNs from 763 patients were examined. LN response classified as complete LN response (LNRS 1 ≥1 LN, no residual tumor in any LN; n = 62, 8.1%), partial LN response (LNRS 1-3 ≥1 LN, residual tumor ≥1 LN; n = 155, 20.3%), poor/no LN response (LNRS 4-5; n = 303, 39.7%), or LN negative (no tumor/regression; n = 243, 31.8%) demonstrated superior discriminatory ability. Mortality was reduced in patients with complete LN response (hazard ratio [HR], 0.35; 95% CI, 0.22 to 0.56), partial LN response (HR, 0.72; 95% CI, 0.57 to 0.93) or negative LNs (HR, 0.32; 95% CI, 0.25 to 0.42) compared with those with poor/no LN response. Primary tumor regression and LN regression were discordant in 165 patients (21.9%).

CONCLUSION

Pathologic LN regression after neoadjuvant chemotherapy was a strong prognostic factor and provides important information beyond pathologic TNM staging and primary tumor regression grading. LN regression should be included as standard in the pathologic reporting of esophagectomy specimens.

Clinical Relevance of the Tumor Location-Modified Laurén Classification System for Gastric Cancer in a Western Population

Background

The Tumor Location-Modified Laurén Classification (MLC) system combines Laurén histologic subtype and anatomic tumor location. It divides gastric tumors into proximal non-diffuse (PND), distal non-diffuse (DND), and diffuse (D) types. The optimum classification of patients with Laurén mixed tumors in this system is not clear due to its grouping with both diffuse and non-diffuse types in previous studies. The clinical relevance of the MLC in a Western population has not been examined.

Methods

A cohort study investigated 404 patients who underwent gastrectomy for gastric adenocarcinoma between 2005 and 2020. The classification of Laurén mixed tumors was evaluated using receiver operating characteristic (ROC) curve analysis and comparison of clinicopathologic characteristics (chi-square). Survival analysis was performed using multivariable Cox regression.

Results

The ROC curve analysis demonstrated a slightly higher area under the curve value for predicting survival when Laurén mixed tumors were grouped with intestinal-type rather than diffuse-type tumors (0.58 vs 0.57). Survival, tumor recurrence, and resection margin positivity in mixed tumors also was more similar to intestinal type. Distal non-diffuse tumors had the best 5-year survival (DND 64.7 % vs PND 56.1 % vs diffuse 45.1 %; p = 0.006) and were least likely to have recurrence (DND 27.0 % vs PND 34.3 % vs diffuse 48.3 %; p = 0.001). Multivariable analysis demonstrated that MLC was an independent prognostic factor for survival (PND: hazard ratio [HR], 1.64; 95 % confidence interval [CI], 1.16–2.32 vs diffuse: HR, 2.20; 95 % CI, 1.56–3.09)

Conclusions

The MLC was an independent prognostic marker in this Western cohort of patients with gastric adenocarcinoma. The patients with PND and D tumors had worse survival than those with DND tumors.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-11252-y.

Resistance to inflammation underlies enhanced fitness in clonal hematopoiesis

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Cost estimation alongside a multi-regional, multi-country randomized trial of antenatal ultrasound in five low-and-middle-income countries

BACKGROUND

Improving maternal health has been a primary goal of international health agencies for many years, with the aim of reducing maternal and child deaths and improving access to antenatal care (ANC) services, particularly in low-and-middle-income countries (LMICs). Health interventions with these aims have received more attention from a clinical effectiveness perspective than for cost impact and economic efficiency.

METHODS

We collected data on resource use and costs as part of a large, multi-country study assessing the use of routine antenatal screening ultrasound (US) with the aim of considering the implications for economic efficiency. We assessed typical antenatal outpatient and hospital-based (facility) care for pregnant women, in general, with selective complication-related data collection in women participating in a large maternal health registry and clinical trial in five LMICs. We estimated average costs from a facility/health system perspective for outpatient and inpatient services. We converted all country-level currency cost estimates to 2015 United States dollars (USD). We compared average costs across countries for ANC visits, deliveries, higher-risk pregnancies, and complications, and conducted sensitivity analyses.

RESULTS

Our study included sites in five countries representing different regions. Overall, the relative cost of individual ANC and delivery-related healthcare use was consistent among countries, generally corresponding to country-specific income levels. ANC outpatient visit cost estimates per patient among countries ranged from 15 to 30 USD, based on average counts for visits with and without US. Estimates for antenatal screening US visits were more costly than non-US visits. Costs associated with higher-risk pregnancies were influenced by rates of hospital delivery by cesarean section (mean per person delivery cost estimate range: 25-65 USD).

CONCLUSIONS

Despite substantial differences among countries in infrastructures and health system capacity, there were similarities in resource allocation, delivery location, and country-level challenges. Overall, there was no clear suggestion that adding antenatal screening US would result in either major cost savings or major cost increases. However, antenatal screening US would have higher training and maintenance costs. Given the lack of clinical effectiveness evidence and greater resource constraints of LMICs, it is unlikely that introducing antenatal screening US would be economically efficient in these settings--on the demand side (i.e., patients) or supply side (i.e., healthcare providers).

TRIAL REGISTRATION

Trial number: NCT01990625 (First posted: November 21, 2013 on https://clinicaltrials.gov ).

Association of haemoglobin levels in the first trimester and at 26-30 weeks with fetal and neonatal outcomes: a secondary analysis of the Global Network for Women's and Children's Health's ASPIRIN Trial

OBJECTIVE

Limited data are available from low- and middle-income countries (LMICs) on the relationship of haemoglobin levels to adverse outcomes at different times during pregnancy. We evaluated the association of haemoglobin levels in nulliparous women at two times in pregnancy with pregnancy outcomes.

DESIGN

ASPIRIN Trial data were used to study the association between haemoglobin levels measured at 6⁺⁰ -13⁺⁶  weeks and 26⁺⁰ -30⁺⁰  weeks of gestation with fetal and neonatal outcomes.

SETTING

Obstetric care facilities in Pakistan, India, Kenya, Zambia, The Democratic Republic of the Congo and Guatemala.

POPULATION

A total of 11 976 pregnant women.

METHODS

Generalised linear models were used to obtain adjusted relative risks and 95% CI for adverse outcomes.

MAIN OUTCOME MEASURES

Preterm birth, stillbirth, neonatal death, small for gestational age (SGA) and birthweight <2500 g.

RESULTS

The mean haemoglobin levels at 6⁺⁰ -13⁺⁶  weeks and at 26-30 weeks of gestation were 116 g/l (SD 17) and 107 g/l (SD 15), respectively. In general, pregnancy outcomes were better with increasing haemoglobin. At 6⁺⁰ -13⁺⁶  weeks of gestation, stillbirth, SGA and birthweight <2500 g, were significantly associated with haemoglobin of 70-89 g/l compared with haemoglobin of 110-129 g/l The relationships of adverse pregnancy outcomes with various haemoglobin levels were more marked at 26-30 weeks of gestation.

CONCLUSIONS

Both lower and some higher haemoglobin concentrations are associated with adverse fetal and neonatal outcomes at 6⁺⁰ -13⁺⁶  weeks and at 26-30 weeks of gestation, although the relationship with low haemoglobin levels appears more consistent and generally stronger.

TWEETABLE ABSTRACT

Both lower and some higher haemoglobin concentrations were associated with adverse fetal and neonatal outcomes at 6-13 weeks and 26-30 weeks of gestation.

Soil net nitrogen mineralisation across global grasslands

Soil nitrogen mineralisation (Nmin), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net Nmin) varies with soil properties and climate. However, because most global-scale assessments of net Nmin are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net Nmin across 30 grasslands worldwide. We find that realised Nmin is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. Potential Nmin only weakly correlates with realised Nmin, but contributes to explain realised net Nmin when combined with soil and climatic variables. We provide novel insights of global realised soil net Nmin and show that potential soil net Nmin data available in the literature could be parameterised with soil and climate data to better predict realised Nmin.

More salt, please: global patterns, responses and impacts of foliar sodium in grasslands

Sodium is unique among abundant elemental nutrients, because most plant species do not require it for growth or development, whereas animals physiologically require sodium. Foliar sodium influences consumption rates by animals and can structure herbivores across landscapes. We quantified foliar sodium in 201 locally abundant, herbaceous species representing 32 families and, at 26 sites on four continents, experimentally manipulated vertebrate herbivores and elemental nutrients to determine their effect on foliar sodium. Foliar sodium varied taxonomically and geographically, spanning five orders of magnitude. Site-level foliar sodium increased most strongly with site aridity and soil sodium; nutrient addition weakened the relationship between aridity and mean foliar sodium. Within sites, high sodium plants declined in abundance with fertilisation, whereas low sodium plants increased. Herbivory provided an explanation: herbivores selectively reduced high nutrient, high sodium plants. Thus, interactions among climate, nutrients and the resulting nutritional value for herbivores determine foliar sodium biogeography in herbaceous-dominated systems.

Routine antenatal ultrasound in low- and middle-income countries: first look - a cluster randomised trial

OBJECTIVE

Ultrasound is widely regarded as an important adjunct to antenatal care (ANC) to guide practice and reduce perinatal mortality. We assessed the impact of ANC ultrasound use at health centres in resource-limited countries.

DESIGN

Cluster randomised trial.

SETTING

Clusters within five countries (Democratic Republic of Congo, Guatemala, Kenya, Pakistan, and Zambia) METHODS: Clusters were randomised to standard ANC or standard care plus two ultrasounds and referral for complications. The study trained providers in intervention clusters to perform basic obstetric ultrasounds.

MAIN OUTCOME MEASURES

The primary outcome was a composite of maternal mortality, maternal near-miss mortality, stillbirth, and neonatal mortality.

RESULTS

During the 24-month trial, 28 intervention and 28 control clusters had 24 263 and 23 160 births, respectively; 78% in the intervention clusters received at least one study ultrasound; 60% received two. The prevalence of conditions noted including twins, placenta previa, and abnormal lie was within expected ranges. 9% were referred for an ultrasound-diagnosed condition, and 71% attended the referral. The ANC (RR 1.0 95% CI 1.00, 1.01) and hospital delivery rates for complicated pregnancies (RR 1.03 95% CI 0.89, 1.20) did not differ between intervention and control clusters nor did the composite outcome (RR 1.09 95% CI 0.97, 1.23) or its individual components.

CONCLUSIONS

Despite availability of ultrasound at ANC in the intervention clusters, neither ANC nor hospital delivery for complicated pregnancies increased. The composite outcome and the individual components were not reduced.

TWEETABLE ABSTRACT

Antenatal care ultrasound did not improve a composite outcome that included maternal, fetal, and neonatal mortality.

A prospective cause of death classification system for maternal deaths in low and middle-income countries: results from the Global Network Maternal Newborn Health Registry

OBJECTIVE

To describe the causes of maternal death in a population-based cohort in six low- and middle-income countries using a standardised, hierarchical, algorithmic cause of death (COD) methodology.

DESIGN

A population-based, prospective observational study.

SETTING

Seven sites in six low- to middle-income countries including the Democratic Republic of the Congo (DRC), Guatemala, India (two sites), Kenya, Pakistan and Zambia.

POPULATION

All deaths among pregnant women resident in the study sites from 2014 to December 2016.

METHODS

For women who died, we used a standardised questionnaire to collect clinical data regarding maternal conditions present during pregnancy and delivery. These data were analysed using a computer-based algorithm to assign cause of maternal death based on the International Classification of Disease-Maternal Mortality system (trauma, termination of pregnancy-related, eclampsia, haemorrhage, pregnancy-related infection and medical conditions). We also compared the COD results to healthcare-provider-assigned maternal COD.

MAIN OUTCOME MEASURES

Assigned causes of maternal mortality.

RESULTS

Among 158 205 women, there were 221 maternal deaths. The most common algorithm-assigned maternal COD were obstetric haemorrhage (38.6%), pregnancy-related infection (26.4%) and pre-eclampsia/eclampsia (18.2%). Agreement between algorithm-assigned COD and COD assigned by healthcare providers ranged from 75% for haemorrhage to 25% for medical causes coincident to pregnancy.

CONCLUSIONS

The major maternal COD in the Global Network sites were haemorrhage, pregnancy-related infection and pre-eclampsia/eclampsia. This system could allow public health programmes in low- and middle-income countries to generate transparent and comparable data for maternal COD across time or regions.

TWEETABLE ABSTRACT

An algorithmic system for determining maternal cause of death in low-resource settings is described.

OSIRIS-REx Contamination Control Strategy and Implementation

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm² of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.

Global Network for Women's and Children's Health Research: probable causes of stillbirth in low- and middle-income countries using a prospectively defined classification system

OBJECTIVE

We sought to classify causes of stillbirth for six low-middle-income countries using a prospectively defined algorithm.

DESIGN

Prospective, observational study.

SETTING

Communities in India, Pakistan, Guatemala, Democratic Republic of Congo, Zambia and Kenya.

POPULATION

Pregnant women residing in defined study regions.

METHODS

Basic data regarding conditions present during pregnancy and delivery were collected. Using these data, a computer-based hierarchal algorithm assigned cause of stillbirth. Causes included birth trauma, congenital anomaly, infection, asphyxia, and preterm birth, based on existing cause of death classifications and included contributing maternal conditions.

MAIN OUTCOME MEASURES

Primary cause of stillbirth.

RESULTS

Of 109 911 women who were enrolled and delivered (99% of those screened in pregnancy), 2847 had a stillbirth (a rate of 27.2 per 1000 births). Asphyxia was the cause of 46.6% of the stillbirths, followed by infection (20.8%), congenital anomalies (8.4%) and prematurity (6.6%). Among those caused by asphyxia, 38% had prolonged or obstructed labour, 19% antepartum haemorrhage and 18% pre-eclampsia/eclampsia. About two-thirds (67.4%) of the stillbirths did not have signs of maceration.

CONCLUSIONS

Our algorithm determined cause of stillbirth from basic data obtained from lay-health providers. The major cause of stillbirth was fetal asphyxia associated with prolonged or obstructed labour, pre-eclampsia and antepartum haemorrhage. In the African sites, infection also was an important contributor to stillbirth. Using this algorithm, we documented cause of stillbirth and its trends to inform public health programs, using consistency, transparency, and comparability across time or regions with minimal burden on the healthcare system.

TWEETABLE ABSTRACT

Major causes of stillbirth are asphyxia, pre-eclampsia and haemorrhage. Infections are important in Africa.

Outbreak of pyrazinamide-monoresistant tuberculosis identified using genotype cluster and social media analysis

SETTING

Monoresistance to pyrazinamide (PZA) has infrequently been associated with Mycobacterium tuberculosis.

OBJECTIVE

To report an outbreak of PZA-monoresistant M. tuberculosis in Virginia involving two genotype clusters from December 2004 to August 2010.

RESULTS

Thirty cases were identified involving a predominantly young, US-born population with histories of substance use and incarceration and a large proportion of children aged <15 years (n= 6, 20%); of these, 23 cases (77%) were culture-confirmed as M. tuberculosis complex. DNA fingerprinting and molecular analysis of the PZA resistance gene, pncA, demonstrated a clonal strain that was not M. bovis. Genotypic data provided the initial link between seemingly unrelated cases, and helped reveal a historic genotype cluster of cases from 2004. Further genotype cluster and contact investigation procedures, including the novel use of the social networking website Facebook.com, revealed additional links between the 2004 and 2009 genotype clusters and described an ongoing, extensive outbreak necessitating an enhanced screening and treatment protocol for contacts.

CONCLUSIONS

This outbreak demonstrates how tuberculosis can spread through a young, vulnerable population. The use of genotypic data and the novel incorporation of social media investigations were critical to understanding the settings and context of infectivity.

Cardiovascular effects of cadence and workload

Increases in cadence may augment SV during submaximal cycling (> 65 % VO2max) via effects of increased muscle pump activity on preload. At lower workloads (45 - 65 % VO2max), SV tends to plateau, suggesting that effects of increases in cadence on pump activity have little influence on SV. We hypothesized that cadence-induced increases in CO at submaximal workloads, where SV tends to plateau, are due to elevations in HR and/or O2 extraction. SV, CO, HR, VO2, and delta a - vO2 were assessed at 80 and 100 rpm during workloads of 50 % (LO) or 65 % (HI) of VO2max in 11 male cyclists. No changes in SV were seen. CO was higher at 100 rpm in 10 of 11 subjects at LO (18.1 +/- 2.7 vs. 17.2 +/- 2.6 L/min). VO2 at both workloads was greater at 100 than 80 rpm as was HR (LO: 129 +/- 11 vs. 121 +/- 10 beats/min; HI: 146 +/- 13 vs. 139 +/- 14 beats/min) (p < 0.05). delta a - vO2 was greater at HI compared to LO at 80 (15.1 +/- 1.6 vs. 13.6 +/- 1.3 ml) and 100 rpm (16.0 +/- 1.7 vs. 15.1 +/- 1.6 ml) (p < 0.05). Results suggest that increases in O2 demand during low submaximal cycling (50 % VO2max) at high cadences are met by HR-induced increases in CO. At higher workloads (65 % VO2max), inability of higher cadences to increase CO and O2 delivery is offset by greater O2 extraction.

Improved tolerability and efficacy in epilepsy patients with extended-release carbamazepine

The authors conducted a 3-month, prospective, open-label study assessing the effects of switching from immediate-release carbamazepine formulations to an equal total daily dose of carbamazepine extended-release capsules (CBZ-ERC) in adolescents and adults with epilepsy. Using validated, epilepsy-specific measures the authors found that switching to CBZ-ERC significantly improved patients' adverse events and quality-of-life measures. Switching to CBZ-ERC also improved seizure control.

Adjunctive antibiotic treatment of women with preterm rupture of membranes or preterm labor

Subclinical infection is associated with preterm rupture of the membranes (PROM) and preterm labor (PTL) in many cases. It was hypothesized that antibiotic treatment might delay delivery and/or decrease infectious morbidity in those with PROM or PTL. Patients from 19 to 34 weeks with PROM and no labor or PTL with intact membranes (but not both) were separately randomized to receive ampicillin versus placebo in addition to usual therapy. There were 36 women with PTL (21 ampicillin/15 placebo) and 84 with preterm PROM (41 ampicillin/43 placebo). Demographically, the treatment and placebo groups were similar. Outcome variables analyzed included delivery delay after treatment, maternal chorioamnionitis/endometritis, Apgar score, neonatal infection, or respiratory distress, and hospital stay. There were no significant differences between the ampicillin and placebo groups in those with PTL or preterm PROM as it concerned outcome parameters. Adjunctive ampicillin used for treatment of idiopathic PTL or preterm PROM was not beneficial in this study.

Occurrence of seizure clusters and status epilepticus during inpatient video-EEG monitoring

OBJECTIVE

To investigate the occurrence of status epilepticus and seizure clusters, and the duration until first seizure at epilepsy monitoring units in the United States.

METHODS

The authors examined the inpatient video-EEG monitoring reports of 514 consecutive patients admitted to five comprehensive epilepsy centers during the year 2000. Time to first seizure, seizure clustering, and seizure duration were ascertained from reports and entered into a database.

RESULTS

In 169 admissions with complex partial seizures (CPSs) or secondarily generalized tonic-clonic (2GTC) seizures, there were 5 (3.0%) patients with status epilepticus, 30 (17.8%) with 4-hour seizure clusters, and 82 (48.5%) with 24-hour seizure clusters. There were no statistically significant differences between centers, except that seizure clusters were observed to be less common at the one center with a formal drug withdrawal protocol. The average time to CPS or 2GTC seizure was 2.1 days; the average number of days to nonepileptic event was 1.2 days (p = 0.001).

CONCLUSIONS

Although status epilepticus is uncommon at epilepsy monitoring units, clusters of seizures are common. Intensive monitoring with drug withdrawal must be performed in a highly supervised, hospitalized setting. Inpatient video-EEG monitoring is efficient, with recording of the first epileptic or nonepileptic events in 2 days or less.

The effects of single-dose fexofenadine, diphenhydramine, and placebo on cognitive performance in flight personnel

BACKGROUND

Sedation and functional impairments are side effects associated with the use of first-generation antihistamines that preclude their use in aviation. Selected second-generation antihistamines do not have such side effects and have been proposed for use in aircrew.

METHODS

Forty-two healthy naval aviation personnel served as subjects in this double-blind, randomized, placebo-controlled crossover study. Subjective drowsiness, cognitive performance, and vigilance were measured under three conditions: 180 mg fexofenadine (F), 50 mg diphenhydramine (D) as a positive control, or placebo (P).

RESULTS

Subjects receiving F vs. D tended to have a faster mean hit reaction time (adjusted mean difference +/- SE, -10.5 +/- 6.8 ms, p = 0.127). Subjects performed faster and better with F vs. D on measures of omission errors and commission errors (p < 0.05). Variable symbol digit coding delayed recall accuracy was better for F vs. D (p = 0.023), and approached significance for shifting attention and divided attention tasks (p = 0.062 and p = 0.057, respectively). Subjects reported significantly more drowsiness (p < 0.005) with D than F.

CONCLUSIONS

Diphenhydramine administration resulted in significant psychomotor decrements compared with fexofenadine, while the effects of fexofenadine were similar to placebo. These results provide additional support for the safe use of fexofenadine by aviation personnel.

Global change and the mulga woodlands of southwest Queensland: greenhouse gas emissions, impacts, and adaptation

The possibility of trading greenhouse gas emission permits as a result of the Kyoto Protocol has spurred interest in developing land-based sinks for greenhouse gases. Extensive grazing lands that have the potential to develop substantial woody biomass are one obvious candidate for such activities. However, such activities need to consider the possible impacts on existing grazing and the possible impacts of continuing CO2 buildup in the atmosphere and resultant climate change. We used simulation models to investigate these issues in the mulga (Acacia aneura) woodlands of southwest Queensland. The simulation results suggest that this system can be managed to act as either a net source or a net sink of greenhouse gases under current climate and CO2 and under a range of global change scenarios. The key component in determining source or sink status is the management of the woody mulga. The most effective means of permanently increasing carbon stores and hence reducing net emissions is to exclude both burning and grazing. There are combinations of management regimes, such as excluding fire with light grazing, which, on average, allows productive grazing but transient carbon storage. The effects of increased CO2 on ecosystem carbon stores were unexpected. Carbon stores increased (7-17%) with doubling of CO2 only in those simulations where burning did not occur, but decreased when burnt. This occurred because the substantial increases in grass growth with doubling of CO2 (34-56%) enabled more fires, killing off the establishing cohorts needed to ensure continued carbon accumulation. On average, the doubling of atmospheric CO2 concentration increased grass growth by 44%, which is identical with mean literature values, suggesting that this result may be applicable in other ecosystems where fire has a similar function. A sensitivity analysis of the CO2 response of mulga showed only minor impacts. We discuss additional uncertainties and shortcomings.

The dynamics of grazed woodlands in southwest Queensland, Australia and their effect on greenhouse gas emissions

This study outlines the development of an approach to evaluate the sources, sinks, and magnitudes of greenhouse gas emissions from a grazed semiarid rangeland dominated by mulga (Acacia aneura) and how these emissions may be altered by changes in management. This paper describes the modification of an existing pasture production model (GRASP) to include a gas emission component and a dynamic tree growth and population model. An exploratory study was completed to investigate the likely impact of changes in burning practices and stock management on emissions. This study indicates that there is a fundamental conflict between maintaining agricultural productivity and reducing greenhouse gas emissions on a given unit of land. Greater agricultural productivity is allied with the system being an emissions source while production declines and the system becomes a net emissions sink as mulga density increases. Effective management for sheep production results in the system acting as a net source (approximately 60-200 kg CO2 equivalents/ha/year). The magnitude of the source depends on the management strategies used to maintain the productivity of the system and is largely determined by starting density and average density of the mulga over the simulation period. Prior to European settlement, it is believed that the mulga lands were burnt almost annually. Simulations indicate that such a management approach results in the system acting as a small net sink with an average net absorption of greenhouse gases of 14 kg CO2 equivalents/ha/year through minimal growth of mulga stands. In contrast, the suppression of fire and the introduction of grazing results in thickening of mulga stands and the system can act as a significant net sink absorbing an average of 1000 kg CO2 equivalents/ha/year. Although dense mulga will render the land largely useless for grazing, land in this region is relatively inexpensive and could possibly be developed as a cost-effective carbon offset for greenhouse gas emissions elsewhere. These results also provide support for the hypothesis that changes in land management, and particularly, suppression of fire is chiefly responsible for the observed increases in mulga density over the past century.

Effects of lovastatin and pravastatin on cognitive function in military aircrew

BACKGROUND

As evidence has accumulated for the role of HMG-CoA reductase inhibitors in the primary prevention of coronary artery disease, younger individuals with no other co-morbid conditions will be increasingly exposed to these agents. Some HMG-CoA reductase inhibitors have been reported to cause impairment of daytime cognitive processes that have the potential to directly impact the ability of pilots and other aircrew to perform. These studies suggested that there might be cognitive effects of these medications that would argue against their routine use in populations whose activities required high, sustained levels of cognitive performance. The objective of this study is to establish the effects of pravastatin and lovastatin on aircrew daytime cognitive function using tests that are correlated with actual cockpit tasks and inflight performance.

METHODS

Military aircrew with hypercholesterolemia were enrolled in the study and assigned to lovastatin, pravastatin or placebo groups. Baseline cognitive and vigilance testing was performed with computerized test instruments. Following a 4-wk treatment period, subjects were retested on both cognitive and vigilance tasks.

RESULTS

Laboratory studies confirmed that both medications were effective in lowering cholesterol. No major treatment-related side effects were encountered. Cognitive performance was not affected by either active treatment, and was not different from that of the placebo group.

CONCLUSIONS

The tested medications did not have significant effects on performance as measured by two computerized performance tests. The data suggest that neither medication has significant effects on flight-related performance.

A Phase II study of topotecan in patients with squamous cell carcinoma of the cervix: a gynecologic oncology group study

OBJECTIVE

The toxicity and activity of intravenous topotecan were assessed in a multicenter Phase II study (GOG 76-U) in patients with advanced, recurrent, or persistent squamous cell carcinoma of the uterine cervix.

METHODS

Intravenous topotecan was administered at 1.5 mg/m2 per day for 5 consecutive days every 4 weeks in patients without prior chemotherapy, aside from chemosensitizing agents used in conjunction with radiotherapy. The study required histologic confirmation of primary diagnosis, adequate performance status, and measurable disease to assess response. A two-stage design for accrual was used to allow for early termination of the study should inadequate response or excessive toxicity be an issue. Modifications of dose were based on hematologic toxicity. Treatment was continued until progression of disease was documented or adverse effects prohibited further therapy.

RESULTS

A total of 49 patients were entered on study: of these 5 were never treated, and 1 was not evaluable for response. More than 88% (38 of 43 patients) had received prior radiotherapy. A median of two courses were administered per patient with a range of 1 to 14 cycles. Grade 4 neutropenia occurred in 68% and grade 4 thrombocytopenia in 18% of patients. Nonhematologic toxic effects were infrequent and not dose-limiting. The overall response rate (complete and partial) was 18.6%. The median progression-free survival was 2.4 months.

CONCLUSIONS

Topotecan administered at this dose and schedule demonstrated moderate activity albeit at a cost of substantial hematologic toxicity in patients with advanced, recurrent, or persistent squamous cell carcinoma of the cervix.

Conservation conflicts across Africa

There is increasing evidence that areas of outstanding conservation importance may coincide with dense human settlement or impact. We tested the generality of these findings using 1 degree-resolution data for sub-Saharan Africa. We find that human population density is positively correlated with species richness of birds, mammals, snakes, and amphibians. This association holds for widespread, narrowly endemic, and threatened species and looks set to persist in the face of foreseeable population growth. Our results contradict earlier expectations of low conflict based on the idea that species richness decreases and human impact increases with primary productivity. We find that across Africa, both variables instead exhibit unimodal relationships with productivity. Modifying priority-setting to take account of human density shows that, at this scale, conflicts between conservation and development are not easily avoided, because many densely inhabited grid cells contain species found nowhere else.

Epidemiology of musculoskeletal and soft tissue injuries aboard a U.S. Navy ship

OBJECTIVE

The objective of this study was to characterize injuries occurring to crew members aboard a U.S. Navy ship.

METHODS

A retrospective review of crew member medical records was conducted covering a 90-day period during which the ship was intermittently at sea. Data on new injuries were collected and sorted. Injuries were classified as soft tissue or musculoskeletal, acute or overuse, and occurring with the ship at sea or in port.

RESULTS

There was a total incidence of 16.5 injuries per 100 man-months. Acute musculoskeletal injuries contributed 2.6 injuries per 100 man-months and resulted in 79 lost and 192.5 modified work days. Overuse musculoskeletal injuries were responsible for 9.3 injuries per 100 man-months and caused 1 lost and 255.5 modified work days. Soft tissue injuries had an incidence of 4.6 injuries per 100 man-months and resulted in no lost and only 106 modified work days. The relative risk of sustaining a soft tissue injury in port compared with at sea was 1.1, but this was not statistically significant. The relative risk of sustaining an acute musculoskeletal injury in port compared with at sea was 3.5 (p = 0.01).

CONCLUSIONS

Overuse musculoskeletal injuries occurred with the greatest incidence, but acute musculoskeletal injuries were responsible for the greatest morbidity. Soft tissue injuries occurred with an intermediate incidence but had the lowest overall morbidity. The safest place for crew members assigned to this Navy ship was aboard that ship at sea. Further studies of this nature could help guide medical efforts at injury treatment and prevention for shipboard personnel.

Characterization and health risk assessment of postmenopausal women with epilepsy

Postmenopausal women with epilepsy represent an understudied patient population. The objectives of this cross-sectional study were to characterize the impact of menopause on seizure activity and to conduct a health risk assessment. We conducted telephone interviews of 40 postmenopausal women with epilepsy concerning the effect of menopause on seizure frequency. We surveyed use of hormone replacement therapy, postmenopausal bone fractures, use of vitamins, and frequency of exercise. The average age and mean seizure duration were 55.8 and 27.6 years, respectively. Twenty-six women had onset of seizure activity before menopause. Of these 26, 3 reported fewer seizures after menopause, 7 reported more seizures, 11 reported no change, and 5 were unsure whether menopause affected their seizures. Only 30% of the 40 women were currently taking hormone replacement therapy. The impact of menopause on seizure activity was variable. Osteoporotic and cardiovascular preventive measures are underutilized. Patient education on these protective measures should be part of the comprehensive treatment approach in this "at-risk" patient population.

Hormone replacement therapy in a postmenopausal woman with epilepsy

OBJECTIVE

To prospectively evaluate the effects of hormone replacement therapy (HRT) on seizure activity in a postmenopausal woman with epilepsy.

BACKGROUND

Postmenopausal women are at an increased risk for cardiovascular disease and osteoporosis secondary to a lack of estrogen's protective effects. As a result, women without known contraindications often take HRT to counteract this risk. Postmenopausal women with epilepsy are at a greater risk for osteoporosis because of the negative effects that certain antiepileptic drugs have on bone density. Clinical studies and experience have shown that hormonal variances across a woman's lifetime play a significant role in seizure activity, but the effects of HRT in postmenopausal women with epilepsy are unknown.

CASE SUMMARY

We report the case of a 51-year-old postmenopausal white woman with epilepsy who presented with frequent vasomotor flushing. To determine individual effects of HRT on seizure activity, therapy was initiated in two three-month phases, with monthly evaluation. A weekly transdermal patch of estradiol 0.1 mg/d was initiated for the first three months. During the second three months, the regimen was expanded to include oral medroxyprogesterone acetate 2.5 mg once daily. Antiepileptic medications and their dosages remained constant. HRT was associated with a decreased incidence of seizures, cessation of vasomotor flushing, improved sleep, and a positive impact on the lipid profile.

CONCLUSIONS

This case report describing the prospective addition of HRT in a postmenopausal woman with epilepsy suggests that HRT can be initiated in certain women to achieve therapeutic benefits without adversely affecting seizure activity.

Centromere-linked microsatellite markers for linkage groups 3, 4, 6, 7, 13, and 20 of zebrafish (Danio rerio)

A large number of interesting mutations affecting development and organogenesis have been identified through genetic screens in zebrafish. Mapping of these mutations to a chromosomal region can be rapidly accomplished using half-tetrad analysis. However, knowledge of centromere-linked markers on every chromosome is essential to this mapping method. Centromeres on all 25 linkage groups have been mapped on the RAPD zebrafish genetic map. However, species specificity and the lack of codominance make RAPD markers less practical for mapping than microsatellite-based markers. On the microsatellite-based genetic map, centromere-linked markers have been identified for 19 linkage groups. No direct evidence has been published linking microsatellite markers to the centromeres of linkage groups 3, 4, 6, 7, 13, and 20. Therefore, we compared the microsatellite-based genetic map with the RAPD map to identify markers most likely linked to the centromeres of these 6 linkage groups. These candidate markers were tested for potential centromere linkage using four panels of half-tetrad embryos derived by early-pressure treatment of eggs from four different female zebrafish. We have identified microsatellite markers for linkage groups 3, 4, 6, 7, 13, and 20 to within 1.7 cM of their centromeres. These markers will greatly facilitate the rapid mapping of mutations in zebrafish by half-tetrad analysis.

An assessment of epilepsy patients' knowledge of their disorder

PURPOSE

Patient education is an effective component of comprehensive care. Studies assessing patient's knowledge of their epilepsy are scarce. We report the first objective study evaluating knowledge of epilepsy patients referred to an American tertiary care center.

METHODS

Two hundred twenty epilepsy patients referred to an epilepsy center completed a knowledge questionnaire. The questionnaire included topics related to safety, compliance, and legal issues of driving and employment. Questionnaire scores were correlated with demographics, number of years with epilepsy, and educational background.

RESULTS

Of 220 patients, 175 were included in study analysis. Thirteen percent (n = 28) were excluded because of the diagnosis of nonepileptic seizures, and 8% (n = 17) were excluded because of having a diagnosis other than epilepsy. The average age and number of years with epilepsy was 34.7 +/- 13 and 14. 4 +/- 13.1, respectively. Neither age (r = 0.20, p </=0.01), number of years with epilepsy (r = 0.09, p = 0.2), nor years of education (r = 0.34, p </=0.01) correlated with questionnaire scores. Thirty percent believed that epilepsy is a mental disorder or contagious. Forty-one percent believed it is appropriate to place an object in a patient's mouth during a seizure to prevent injury. Two of the lowest scores, 13.6% and 47.5%, pertained to the legal issues of driving and employment, respectively.

CONCLUSIONS

Patients with epilepsy are not knowledgeable about their disorder. This is true regardless of age, educational background, or number of years with epilepsy. There is a need for educational intervention in this population, particularly related to injury prevention and the legalities of driving and employment.

Referral characteristics of primary care physicians for seizure patients

PURPOSE

To investigate primary care physicians' behavior with respect to referral patterns, antiepileptic drug (AED) initiation, and level of comfort in managing seizure patients.

METHODS

A cross-sectional descriptive study design was used for collecting and analyzing data. A 20-item survey was developed and mailed to 8,195 primary care physicians including family practitioners, internal medicine physicians, and obstetrics-gynecologists throughout the state of Ohio; 504 primary care physicians that interact regularly with epilepsy patients responded to the survey.

RESULTS

Two patterns of referral emerged. Data showed that the majority (n = 382) of physicians refer >/=50% of their patients, but a minority of physicians (n = 122) refer <50% of their patients. Differences between the two groups existed in three of the four research questions asked: who initiates AED therapy, comfort level, and percentage of patients referred to a neurologist. Influence of managed care on decision making was not different between the two groups.

CONCLUSIONS

A minority of primary care physicians rate themselves very comfortable with seizure patients. These same physicians refer a minority of their patients to a neurologist. As a whole, however, primary care physicians refer a majority of their seizure patients to a neurologist. Neurologists evaluate most seizure patients because most primary care physicians claim not to be extremely comfortable with evaluation and treatment of seizures. We conclude that neurologists play an essential role in the treatment of most seizure patients.

Ethylnitrosourea induces neoplasia in zebrafish (Danio rerio)

The zebrafish (Danio rerio) has been successfully used to discover hundreds of genes involved in development and organogenesis. To address the potential of zebrafish as a cancer model, it is important to determine the susceptibility of zebrafish to tumors. Germ line mutations are most commonly induced for zebrafish mutant screens by exposing adult male zebrafish to the alkylating agent, ethylnitrosourea (ENU). To determine whether ENU induces tumors, we compared the incidence of tumors in ENU-treated fish with untreated controls. Interestingly, 18 of 18 (100%) fish mutagenized with either 2.5 or 3.0 mM ENU developed epidermal papillomas, which numbered 1 to 22 per fish, within 1 year of treatment. The induced epidermal lesions included epidermal hyperplasia, flat papillomas (0.2 to 1.2 mm), and pedunculated papillomas (1.2 to 8 mm in greatest dimension), but no skin cancers. Angiogenesis was evident in papillomas larger than approximately 1 mm. All but two papillomas contained the three cell types (keratinocytes, club, and mucous cells) of normal zebrafish epidermis; histologic variants lacked either club cells or mucous cells. Two cavernous hemangiomas and a single malignant peripheral nerve sheath tumor were also found in the treated fish. None of five untreated controls developed tumors. These studies establish the feasibility of the zebrafish as an experimental model for the study of skin tumors.

Alternative medicine use by patients with epilepsy

Purpose. The objectives of this study were, first, to determine the prevalence, characteristics, and demographic patterns of alternative medicine (AM) use in patients with epilepsy, and second, to ascertain the extent to which these patients inform the neurologist of AM use. Methods. Surveys were distributed randomly to patients attending a tertiary care epilepsy clinic. The survey assessed use of specific herbal medicine/dietary supplements, along with other forms of AM. Results. Of 150 surveys distributed, 92 were used for analysis. Twenty-two patients with epilepsy (24%) used AM, and only 31% of AM users reported such to their neurologists. Massage and herbs/supplements were used the most, and only two patients used AM specifically for treatment related to epilepsy. Conclusions. A sizable minority of patients with epilepsy who visit our tertiary care clinic use AM. Health professionals should actively monitor therapies to ensure safety and effectiveness with combined traditional medicine and AM use.

Investigations of crashes involving pregnant occupants

Case reports of 16 crashes involving pregnant occupants are presented that illustrate the main conclusions of a crash-investigation program that includes 42 crashes investigated to date. Some unusual cases that are exceptions to the overall trends are also described. The study indicates a strong association between adverse fetal outcome and both crash severity and maternal injury. Proper restraint use, with and without airbag deployment, generally leads to acceptable fetal outcomes in lower severity crashes, while it does not affect fetal outcome in high-severity crashes. Compared to properly restrained pregnant occupants, improperly restrained occupants have a higher risk of adverse fetal outcome in lower severity crashes, which comprise the majority of all motor-vehicle collisions.

Hearing loss and automobile airbag deployments

In an on-going research program, on the causation of injuries in motor vehicle accidents, at the University of Michigan Transportation Research Institute, crashes with airbags have been, and are continuing to be, investigated. In order to determine the occurrence, if any, of 'hearing problems' associated with airbag deployments, drivers and passengers who had been involved in 'airbag' automobile crashes were interviewed by telephone. From the crashes investigated, 225 attempts were made to contact drivers who were exposed to airbag deployments. From these telephone interviews, contacts were made with 177 car occupants. Only three reported that they had experienced any type of hearing-related problems subsequent to their crash. One other case is reported of a driver who had pre-crash hearing loss. It appears that permanent hearing deficit due to airbag deployment, both in cars with the steering wheel airbag alone, and in those with a passenger side airbag, is an infrequent event (1.7%) from the data of this study.

Assessing the needs of pharmacists and physicians in caring for patients with epilepsy

OBJECTIVE

To obtain primary care physicians' and community pharmacists' opinions of the Pharmacist Note, a model epilepsy patient profile maintained by the pharmacist and transmitted to the physician as needed, and the information it contains.

DESIGN

A cross-sectional descriptive study design was used for collecting and analyzing data. Separate surveys were developed and mailed to physicians and pharmacists.

PARTICIPANTS

554 primary care physicians and 114 community pharmacists in Ohio who interact regularly with epilepsy patients.

MAIN OUTCOME MEASURES

Pharmacist and physician opinions on the Pharmacist Note program.

RESULTS

Physicians ranked seizure frequency as their most useful piece of information, followed by medication compliance and drug interaction screening. For medication profile and drug interaction screening, most physicians currently use themselves as their primary source of information, although a significant number would prefer to use pharmacists as information sources in these areas (p < .05). A majority (62%) would like to have pharmacists more involved in the care of their patients. Pharmacists identified lack of time and lack of appointments with patients, inadequate pharmacy staff, and insufficient reimbursement as barriers to implementing the Pharmacist Note program.

CONCLUSION

Physicians desire pharmacist involvement in specific areas of care for patients with epilepsy, and the feasibility of implementing the Pharmacist Note and similar programs appears promising. However, pharmacists identified barriers to implementation, and these barriers need to be addressed if this type of program is to be successful.

A descriptive analysis of "not aeronautically adaptable" dispositions in the U.S. Navy

BACKGROUND

All aviation personnel in the U.S. Navy are evaluated for aeronautical adaptability (AA) in both initial and periodic examinations and for daily aeromedical disposition. By definition, all aviation personnel with a diagnosed personality disorder or those with maladaptive personality traits that have had a documented effect on safety of flight, crew coordination, or mission completion, are determined to be Not Aeronautically Adapted (NAA).

METHODS

NAA dispositions were examined for demographic data, basis for disposition, and frequency of personality features.

RESULTS

NAA dispositions were made on the basis of personality disorders and maladaptive personality traits in 29% and 35% of the cases, respectively. The officer and enlisted NAA dispositions were distinctly different in terms of frequency of personality features. Obsessive-compulsive features were present in 58% of officer and 10% of enlisted NAA dispositions. Dependent and avoidant features were present in excess in comparison to psychologically healthy aviators, suggesting the incompatibility of these features with aviation.

Amnioinfusion-induced malpresentation

Amnioinfusion is a valuable and common intrapartum procedure for the relief of cord compression and to dilute thick meconium. Like most procedures, it is not without risk and we report a case of malpresentation following amnioinfusion. Intrapartum fetal demise occurred after malpresentation during amnioinfusion resulting in a change of fetal presentation from vertex to unrecognized shoulder presentation. Further study is needed regarding changes in volume of amniotic fluid and saline as well as intrauterine manipulation and the effect on fetal presentation. Careful attention must be paid to infused volumes during amnioinfusion.

Arachnoid cysts: how do postsurgical cyst size and seizure outcome correlate?

Arachnoid cysts (ACs) are congenital cystic brain malformations associated with epilepsy. The purpose of this study was to determine the effect of surgical intervention of ACs on cyst size and seizure outcome. We reviewed the world's medical literature dealing with surgically treated ACs in epilepsy patients. Our study included only cases, in which the relationship between pre-and postoperative CT-size of the AC and seizure outcome was described. We also included six patients with ACs and epilepsy treated surgically at the University of Mainz. We analyzed postoperative AC size and seizure outcome with respect to mode of operation, cyst location, and patients' age. A total of 76 patients was reviewed. Sixty (79%) patients had a smaller AC postoperatively. Forty-six of those 60 (76.6%) experienced seizure improvement. Thirteen patients (21.6%) remained unchanged and one patient (1.8%) worsened. In 16 of the 76 patients (21%) the postoperative AC size was unchanged. Eight of those 16 patients improved. Six patients (37.5%) remained unchanged and two (12.5%) worsened. A positive correlation between postoperative AC size and seizure outcome was well demonstrated among patients treated by cyst fenestration, needle aspiration, or internal shunting. Among patients treated by cystoperitoneal shunting this direct correlation was less clear. Seizure outcome correlates directly with postoperative AC size. Seizure reduction is associated with decreased AC size postoperatively and depends on the mode of operation. Based on these data we would expect that patients with epilepsy secondary to ACs would demonstrate improved seizure control with lower AC volume. Conversely, we might expect increasing AC size to correlate with worse seizure control. This relationship may guide physicians in efficacy and timely patient management.

Fenestration of porencephalic cysts to the lateral ventricle: experience with a new technique for treatment of seizures

BACKGROUND

Porencephalic cysts are brain cavities resulting from perinatal vascular occlusion and are commonly associated with severe neurological deficits and medically intractable epilepsy. Thirty-seven children presenting to the University of Münster with intractable seizures because of a porencephalic cyst were treated by uncapping and fenestration of these cysts to the lateral ventricle between 1978 and 1992. We conducted the following study to determine the efficacy and safety of the uncapping and fenestration procedure for the treatment of seizures.

METHODS

We reviewed all cases retrospectively and assessed the outcome of these patients with regard to seizures, paresis, and perioperative complications.

RESULTS

Of 37 children, 23 (62%) were seizure-free postoperatively. Nine patients (24%) had a reduction of seizures and five children (14%) remained unchanged. Of 30 patients with preoperative hemiparesis, 11 (30%) improved after the operation. The leading postoperative problem was a subcutaneous/subgaleal cushion of CSF, which affected 12 children (12 of 37). A dural patch covering the iatrogenic dural defect could not prevent or reduce postoperative CSF leakage, but prolonged the postoperative fever period. Postoperative fever occurred in 36 children (36 of 37) and was caused by an aseptic meningitis.

CONCLUSIONS

Children with intractable seizures and porencephalic cysts benefit from uncapping and cyst fenestration to the lateral ventricle. Concomitant perioperative complications are mild and are easily treated.

Genetic dissection of vertebrate processes in the zebrafish: a comparison of uniparental and two-generation screens

Genetic dissection is used to identify important genes in biological processes and is accomplished through the generation and study of mutations in model organisms. In diploid organisms, recessive mutations must be rendered hemizygous or homozygous for the mutant phenotype to be detected. In zebrafish (Danio rerio), this can be accomplished in two ways: (i) crosses between siblings who are potential carriers (in two-generation screens) and (ii) the generation of uniparental progeny. Two-generation screens have been the most productive to date but require substantial resources. However, uniparental screens involving haploids and half-tetrads (products of meiosis I) have also been productive, and require more modest resources. In genetic screens, the fraction of an average genome that is heterozygous (heterozygosity index) is inversely proportional to the likelihood that separate recessive mutations will be homozygous at the same time. Heterozygosity indices for haploid, half-tetrad, and two-generation screens are 0, 66, and 87.5%, respectively. Family sizes required to minimize bias in half-tetrad screens are also calculated. We conclude that gynogenetic half-tetrad screens are genetically robust and technically accessible to the independent researcher. The increasingly powerful genetic and experimental tools available for work with zebrafish can be used to address a broad range of questions in vertebrate biology.

Lifelong self-directed learning using a computer database of clinical questions

Physicians often have self-perceived knowledge gaps when they are seeing patients. Traditional continuing medical education is designed to meet the knowledge gaps of groups rather than individual physicians with specific patient problems. Physicians with clinical information needs are advised to critically evaluate high-quality original research in order to practice "evidence-based medicine." But this advice may be unrealistic for busy clinicians. We propose a system for documenting self-perceived information needs using a computer database. Concise answers to these needs are included in the database along with reference citations supporting the answers. The system tracks continuing education efforts, directs patient care decisions, and focuses lifelong learning on relevant topics. We emphasize the importance of being sensitive to personal information needs and the benefits of maintaining a record of these needs.

Activation of the focal adhesion kinase signal transduction pathway in cervical carcinoma cell lines and human genital epithelial cells immortalized with human papillomavirus type 18

The inappropriate activation of protein-tyrosine kinases (PTKs) has been associated with initiation and progression of several types of human cancers. We therefore postulated that immortalization by DNA tumor viruses results in the induction of PTKs fundamental to these processes. An RT-PCR-based screen was thus used to identify PTKs that were abundantly expressed in HPV-18-immortalized epithelial cells and HPV-containing carcinoma cell lines. One of the genes isolated in this screen was the focal adhesion kinase (FAK; pp125FAK), a cytoplasmic protein kinase that is activated in v-src transformed cells or by stimulation with mitogenic polypeptides. FAK also becomes catalytically active upon integrin engagement with extracellular matrix proteins, such as fibronectin. We found that FAK expression and activity were significantly elevated in HPV-18 E6/E7-immortalized human genital epithelial cells relative to their primary cell counterparts. Protein expression and tyrosine phosphorylation of the putative FAK substrate, paxillin, were also notably increased upon HPV-18 immortalization of genital epithelial cells and in HPV-containing cervical carcinoma cell lines. Most significantly, these cells expressed markedly higher levels of both intracellular and extracellular fibronectin, thus providing a mechanism for activation of FAK and increased tyrosine phosphorylation of paxillin. These findings suggest a role for the integrin/FAK-mediated signaling pathway in cervical carcinogenesis and represent one of the first demonstrations of a tyrosine kinase whose activity is elevated following viral immortalization.

Structure-activity relationships of N-hydroxyurea 5-lipoxygenase inhibitors

The discovery of second generation N-hydroxyurea 5-lipoxygenase inhibitors was accomplished through the development of a broad structure-activity relationship (SAR) study. This study identified requirements for improving potency and also extending duration by limiting metabolism. Potency could be maintained by the incorporation of heterocyclic templates substituted with selected lipophilic substituents. Duration of inhibition after oral administration was optimized by identification of structural features in the proximity of the N-hydroxyurea which correlated to low in vitro glucuronidation rates. Furthermore, the rate of in vitro glucuronidation was shown to be stereoselective for certain analogs. (R)-N-[3-[5-(4-Fluorophenoxy)-2-furyl]-1-methyl-2-propynyl]-N-hydroxyure a (17c) was identified and selected for clinical development.

Panic with a twist: an unusual presentation of combined psychiatric and neurologic symptoms in a tactical jet aviator

A 28-yr-old Naval F-14 aviator presented with complaints of flight-related anxiety occurring intermittently over an 18-mo period. Symptoms included sensation of strangeness, concern over the welfare of his radar intercept officer, flushing, nausea, and intense need to immediately land the aircraft. He also described a 6-mo history of episodes wherein he would see "shooting stars" in the periphery of his vision, accompanied by dizziness and disorientation. These latter attacks were always precipitated by head turning, usually in combination with positive Gz maneuvers, and were relieved by head straightening. The anxiety symptoms were consistent with a form of panic attack, but the neurological symptoms provoked further workup. Magnetic resonance cerebral angiogram demonstrated a dominant right vertebral artery and hypoplastic left vertebral artery. All symptoms resolved once the aviator was removed from flying the aircraft. After a year of follow-up with an aviation psychiatrist, he remained asymptomatic and was reassigned to maritime patrol aircraft. This case illustrates a difficult diagnostic, therapeutic, and disposition challenge. This aviator suffered from a complex interaction of neurologic and psychiatric manifestations having a common inciting stimulus, namely flying the F-14 Tomcat. A promising aviation career was preserved upon removal of that stimulus.

The efficacy of protoporphyrin as a predictive biomarker for lead exposure in canvasback ducks: Effect of sample storage time

We used 363 blood samples collected from wild canvasback dueks (Aythya valisineria) at Catahoula Lake, Louisiana, U.S.A. to evaluate the effect of sample storage time on the efficacy of erythrocytic protoporphyrin as an indicator of lead exposure. The protoporphyrin concentration of each sample was determined by hematofluorometry within 5 min of blood collection and after refrigeration at 4 °C for 24 and 48 h. All samples were analyzed for lead by atomic absorption spectrophotometry. Based on a blood lead concentration of ≥0.2 ppm wet weight as positive evidence for lead exposure, the protoporphyrin technique resulted in overall error rates of 29%, 20%, and 19% and false negative error rates of 47%, 29% and 25% when hematofluorometric determinations were made on blood at 5 min, 24 h, and 48 h, respectively. False positive error rates were less than 10% for all three measurement times. The accuracy of the 24-h erythrocytic protoporphyrin classification of blood samples as positive or negative for lead exposure was significantly greater than the 5-min classification, but no improvement in accuracy was gained when samples were tested at 48 h. The false negative errors were probably due, at least in part, to the lag time between lead exposure and the increase of blood protoporphyrin concentrations. False negatives resulted in an underestimation of the true number of canvasbacks exposed to lead, indicating that hematofluorometry provides a conservative estimate of lead exposure.

The rev-responsive element negatively regulates human immunodeficiency virus type 1 env mRNA expression in primate cells

The human immunodeficiency virus type 1 (HIV-1) Rev protein mediates the accumulation of unspliced and singly spliced viral transcripts within the cytoplasm of infected cells, late in the infection cycle, leading to the expression of the viral structural proteins, Gag, Pol, and Env. Rev binds to a complex RNA structure, the Rev-responsive element (RRE), present in all Rev-responsive viral transcripts, relieving their nuclear sequestration. The precise mechanism by which RRE-containing transcripts are retained within the nucleus in the absence of Rev protein is not well understood. We previously demonstrated that the RRE alone plays a crucial role in the nuclear retention of RRE-containing env transcripts in stably transfected Drosophila cells. Here we extend our previous observations and demonstrate that the RRE is a principal determinant of nuclear retention for envelope transcripts in primate cells and, in particular, human CD4+ T cells.

Effect of cAMP binding site mutations on the interaction of cAMP receptor protein with cyclic nucleoside monophosphate ligands and DNA

Although cAMP binding to wild type cAMP receptor protein (CRP) induces specific DNA binding and activates transcription, cyclic nucleoside monophosphate (cNMP) binding to the CRP mutant Ser128 --> Ala does not, whereas the double CRP mutant Thr127 --> Leu/Ser128 --> Ala activates transcription even in the absence of cNMP. Isothermal titration calorimetry measurements on the cNMP binding reactions to the S128A and T127L/S128A mutants show that the reactions are mainly entropically driven as is cAMP binding to CRP. In contrast to cAMP binding to CRP, the binding reactions are noncooperative and exothermic with binding enthalpies (DeltaHb) ranging from -23.4 +/- 0.9 kJ mol-1 for cAMP binding to S128A at 39 degrees C to -4.1 +/- 0.6 kJ mol-1 for cAMP binding to T127L/S128A at 24 degrees C and exhibit enthalpy-entropy compensation. To account for the inactivity of the S128A mutant, in vitro and in vivo DNA binding experiments were performed on the cAMP-ligated S128A mutant. The cAMP-ligated S128A mutant binds to the consensus DNA binding site with approximately the same affinity as that of cAMP-ligated CRP but forms a different type of complex, which may account for loss of transcriptional activity by the mutant. Energy minimization computations on the cAMP-ligated S128A mutant show that amino acid conformational differences between S128A and CRP occur at Ser179, Glu181, and Thr182 in the center of the DNA binding site, implying that these conformational changes may account for the difference in DNA binding.

Endometrial stromal sarcoma with focal smooth muscle differentiation: recurrence after 17 years: a follow-up report with discussion of the nomenclature

In 1977, a case report was published describing a 28-year-old women with an endometrial stromal tumor that showed foci of myogenic differentiation. The term "stromomyoma" was introduced to encompass both this type of neoplasm as well as "uterine neoplasms resembling ovarian sex-cord tumors" (UTROSCTs). More than 17 years later, the tumor recurred, involving the right ovary, sigmoid colon, small bowel, abdominal wall and omentum. The histologic and electron microscopic similarities between the recurrent tumor and the primary neoplasm were confirmed. Applying the recent classification and diagnostic criteria of endometrial mesenchymal neoplasms, we have concluded that this tumor was a low-grade endometrial stromal sarcoma (LGSS). The formerly proposed term "stromomyoma" implies a benign tumor, in contrast to the obviously malignant nature of this particular tumor. Focal myogenic differentiation of LGSS is not an uncommon finding and does not warrant a separate diagnostic or prognostic entity. UTROSCTs and endometrial stromal sarcomas are two separate diagnostic entities, and combining them under an inclusive terminology is not appropriate.