Tar pollution event (2021) at the Southeastern Levantine oligotrophic basin, short-term impacts and operational oceanography perspectives

The Levantine basin (LB) in the Southeastern Mediterranean Sea is a high-risk oil pollution hot spot owing to its dense maritime traffic and intense oil and gas exploration and exploitation activities. In February 2021 the Israeli LB shorelines were impacted by an exceptional tar pollution event (~550 tons; average distribution: ~3 kg tar m-1 front beach) of an unknown oil spill source. Here we report on the immediate numerical modelling assessment of the oil spill propagation and tar distribution; operational use of underwater gliders for tracking water column anomalies of dissolved polycyclic aromatic hydrocarbons (PAHs) and turbidity signals; the beached tar composition and amounts and the short-term response of the microbial population along the ~180 km shoreline. This pollution event emphasizes the need for improving the early warning systems for oil spills and implementing continuous operational monitoring at high-risk, ecologically sensitive and valuable resource areas like the Israeli LB waters.

The Impact of Injection Distance to Bifurcations on Yttrium-90 Distribution in Liver Cancer Radioembolization

PURPOSE

To model the effect of the injection location on the distribution of yttrium-90 (⁹⁰Y) microspheres in the liver during radioembolization using computational simulation and to determine the potential effects of radial movements of the catheter tip.

MATERIALS AND METHODS

Numerical studies were conducted using images from a representative patient with hepatocellular carcinoma. The right hepatic artery (RHA) was segmented from contrast-enhanced cone-beam computed tomography scans. The blood flow was investigated in the trunk of the RHA using numerical simulations for 6 injection position scenarios at 2 sites located at a distance of approximately 5 and 20 mm upstream of the first bifurcation (RHA diameters of approximately 4.6 mm). The ⁹⁰Y delivery to downstream vessels was calculated from the simulated hepatic artery hemodynamics.

RESULTS

Varying the injection location along the RHA and across the vessel cross-section resulted in different simulated microsphere distributions in the downstream vascular bed. When the catheter tip was 5 mm upstream of the bifurcation, ⁹⁰Y distribution in the downstream branches varied by as much as 53% with a 1.5-mm radial movement of the tip. However, the catheter radial movement had a weaker effect on the microsphere distribution when the injection plane was farther from the first bifurcation (20 mm), with a maximum delivery variation of 9% to a downstream branch.

CONCLUSIONS

An injection location far from bifurcations is recommended to minimize the effect of radial movements of the catheter tip on the microsphere distribution.

Lurasidone in adolescents with schizophrenia: Sustained remission and recovery during 2 years of open-label treatment

Introduction

Compared with adult onset, early onset schizophrenia is typically characterized by greater illness severity and less favorable prognosis.

Objectives

To evaluate the proportion of adolescent patients with schizophrenia who achieved sustained remission and recovery during 2 years of treatment with lurasidone.

Methods

Patients aged 13-17 years with a DSM-IV-TR diagnosis of schizophrenia, and a Positive and Negative Symptom Scale (PANSS) total score ≥70 and <120, were randomized to 6 weeks of double-blind (DB), fixed-dose treatment with lurasidone (37 or 74 mg/d) or placebo. Patients who completed 6 weeks of DB treatment were eligible to enroll in a 2-year, open-label (OL), flexible dose extension study of lurasidone (18.5-74 mg/d). Criteria for sustained remission, were the 6-month consensus criteria summarized by Andreasen (Am J Psych 2005;162:441-9). Criteria for sustained recovery consisted of meeting sustained remission criteria with a Children’s Global Assessment Scale (CGAS) score ≥70 for at least 6-months indicating no clinically significant functional impairment.

Results

A total of 271 patients completed the 6-week DB study and entered the extension study, and 186 (68.6%) and 156 (57.6%) completed 52 weeks and 104 weeks of treatment, respectively. During OL treatment with lurasidone, 52.8% met sustained remission criteria, with a Kaplan-Meier (KM) estimate of 64.1 weeks for median time to sustained remission; and 28.8% met sustained recovery criteria, KM estimate of 104.6 weeks for median time to sustained recovery.

Conclusions

For adolescents with schizophrenia, treatment with lurasidone was associated with high rates of sustained remission and sustained recovery over a two-year period.

Disclosure

Employee of Sunovion Pharmaceuticals Inc. The study summarized in this Abstract was supported by funding from Sunovion Pharmaceuticals Inc

Efficacy and safety of lurasidone in adolescents and young adults with schizophrenia: Pooled analysis of double-blind, placebo-controlled 6-week studies

Introduction

Onset of schizophrenia commonly occurs during late adolescence or early adulthood and is often characterized by greater symptom severity and impairment.

Objectives

To evaluate the efficacy and safety of lurasidone in the treatment of acute schizophrenia in adolescents and young adults.

Methods

The 4 studies in this pooled analysis used similar study designs. Patients (ages 13-25 years) were randomized to 6 weeks of double-blind, placebo-controlled treatment with once-daily lurasidone (37 mg, 74 mg, 111 mg, 148 mg). The primary outcome was endpoint change in the Positive and Negative Syndrome Scale (PANSS) total score; secondary measures included the Clinical Global Impression, Severity scale (CGI-S).

Results

The safety population consisted of 537 patients; 79.1% completed the studies. Treatment with lurasidone was significant (P<0.001) at Week 6 endpoint for change in the PANSS total score, with higher effect sizes (ES) at higher doses (37 mg, 0.53; 74 mg, 0.57; 111 mg, 0.67; 148 mg, 1.35); significance was also observed for change in the CGI-S (37 mg, 0.51; 74 mg, 0.49; 111 mg, 0.57; 148 mg, 1.75). For lurasidone (combined doses), 3 adverse events occurred with a frequency ≥5% (nausea, 13.5%; somnolence, 12.1%; akathisia, 10.1%); 4.8% of patients discontinued due to an adverse event. At LOCF-endpoint, 3.6% of patients had weight gain ≥7%, and 1.5% had weight loss ≥7%. Minimal median changes were observed at endpoint in metabolic lab values.

Conclusions

In adolescents and young adults with schizophrenia, treatment with lurasidone in doses of 37-148 mg/d was a safe, well-tolerated, and effective treatment.

Disclosure

Presenter is an employee of Sunovion Pharmaceuticals Inc. The study summarized in this Abstract was supported by Funding from Sunovion Pharmaceuticals Inc.

Cross-Modal Data Programming Enables Rapid Medical Machine Learning

A major bottleneck in developing clinically impactful machine learning models is a lack of labeled training data for model supervision. Thus, medical researchers increasingly turn to weaker, noisier sources of supervision, such as leveraging extractions from unstructured text reports to supervise image classification. A key challenge in weak supervision is combining sources of information that may differ in quality and have correlated errors. Recently, a statistical theory of weak supervision called data programming has shown promise in addressing this challenge. Data programming now underpins many deployed machine-learning systems in the technology industry, even for critical applications. We propose a new technique for applying data programming to the problem of cross-modal weak supervision in medicine, wherein weak labels derived from an auxiliary modality (e.g., text) are used to train models over a different target modality (e.g., images). We evaluate our approach on diverse clinical tasks via direct comparison to institution-scale, hand-labeled datasets. We find that our supervision technique increases model performance by up to 6 points area under the receiver operating characteristic curve (ROC-AUC) over baseline methods by improving both coverage and quality of the weak labels. Our approach yields models that on average perform within 1.75 points ROC-AUC of those supervised with physician-years of hand labeling and outperform those supervised with physician-months of hand labeling by 10.25 points ROC-AUC, while using only person-days of developer time and clinician work—a time saving of 96%. Our results suggest that modern weak supervision techniques such as data programming may enable more rapid development and deployment of clinically useful machine-learning models.

•

We propose cross-modal data programming (XMDP) for machine learning (ML) in medicine

•

XMDP reduces labeling costs by 96% versus hand labeling on 4 diverse medical ML tasks

•

Days of XMDP and years of hand labeling often yield similarly performing models

•

XMDP performance continually improves as more unlabeled data becomes available

Machine learning can achieve record-breaking performance on many tasks, but machine learning development is often hindered by insufficient hand-labeled data for model training. This issue is particularly prohibitive in areas such as medical diagnostic analysis, where data are private and require expensive labeling by clinicians.

A promising approach to handle this bottleneck is weak supervision, where machine learning models are trained using cheaper, noisier labels. We extend a recent, theoretically grounded weak supervision paradigm—data programming—wherein subject matter expert users write labeling functions to label training data imprecisely rather than hand-labeling data points. We show that our approach allows us to train machine learning models using person-days of effort that previously required person-years of hand labeling. Our methods could enable researchers and practitioners to leverage machine learning models over high-dimensional data (e.g., images, time series) even when labeled training sets are unavailable.

The Efficacy of Lurasidone on PANSS Subscales in Adolescent Patients with Schizophrenia: Results from a 6-week, Double-blind, Placebo-controlled, Multicenter Study

Introduction

Lurasidone is an atypical antipsychotic that demonstrated efficacy in the treatment of adults with schizophrenia in the dose range of 37–148 mg/day.

Objective/Aims

The objective of this analysis was to evaluate the efficacy of lurasidone in adolescent patients with schizophrenia.

Methods

Adolescents (13–17 years old) diagnosed with schizophrenia were randomly assigned to six weeks of double-blind treatment with lurasidone 37 mg/day, 74 mg/day or placebo. Changes from baseline to week 6 in PANSS total and subscale (positive, negative, general psychopathology, excitability) scores were evaluated using mixed-model repeated-measures analysis.

Results

A total of 326 patients (mean age, 15.4 years) were randomized and received lurasidone 37 mg/day (n = 108), 74 mg/day (n = 106), or placebo (n = 112). The PANSS total score at week 6 demonstrated a placebo-adjusted, least-squares (LS) mean improvement of –8.0 (P < 0.001; effect size [ES], 0.51) for the 37 mg/day group and –7.7 (P < 0.001; ES = 0.48) for the 74 mg/day group. Placebo-adjusted LS mean change for lurasidone 37 mg/day and 74 mg/day, respectively, was –3.2 (P < 0.001; ES = 0.62) and –3.2 (P < 0.001; ES = 0.60) on the PANSS positive subscale, –1.7 (P = 0.011; ES = 0.41) and –1.6 (P = 0.022; ES = 0.35) on the PANSS negative subscale, –2.8 (P = 0.012; ES = 0.38) and –2.8 (P = 0.011; ES = 0.37) on the PANSS general psychopathology subscale, and –1.1 (P = 0.016; ES = 0.36) and –1.8 (P < 0.001; ES = 0.53) on the PANSS excitability subscale.

Conclusions

In adolescent patients with schizophrenia, lurasidone (37 mg/day and 74 mg/day) demonstrated statistically significant efficacy and clinically meaningful improvement across a wide spectrum of symptoms associated with schizophrenia. Sponsored by Sunovion Pharmaceuticals Inc. ClinicalTrials.gov identifier: NCT01911429.

Disclosure of interest

Dr Correll reports being a consultant and/or advisor for Alkermes, Forum Pharmaceuticals Inc., Gerson Lehrman Group, IntraCellular Therapies, Janssen/J&J, Lundbeck, Medavante, Medscape, Otsuka, Pfizer Inc, ProPhase, Sunovion Pharmaceuticals Inc., Supernus, Takeda, and Teva providing expert testimony for Bristol-Myers Squibb Company, Janssen, and Otsuka serving on a Data Safety Monitoring Board for Lundbeck and Pfizer Inc and receiving grant support from Takeda. Drs Goldman, Cucchiaro, Deng and Loebel are employees of Sunovion Pharmaceuticals Inc.

Improving End-of-Life Care and Advance Care Planning for Frail Older Adults in Canad

We present five Key Concepts that describe priorities for improving end-of-life care for frail older adults in Canada, and recommendations based on each Key Concept. Key Concept #1: Our end-of-life care system is focused on cancer, not frailty. Key Concept #2: We need better strategies to systematically identify frail older adults who would benefit from a palliative approach. Key Concept #3: The majority of palliative and end-of-life care will be, and should be, provided by clinicians who are not palliative care specialists. Key Concept #4: Organizational change and innovative funding models could deliver far better end-of-life care to frail individuals for less than we are currently spending. Key Concept #5: Improving the quality and quantity of advance care planning for frail older adults could reduce unwanted intensive care and costs at the end of life, and improve the experience for individuals and family members alike.

Snorkel MeTaL: Weak Supervision for Multi-Task Learning

Many real-world machine learning problems are challenging to tackle for two reasons: (i) they involve multiple sub-tasks at different levels of granularity; and (ii) they require large volumes of labeled training data. We propose Snorkel MeTaL, an end-to-end system for multi-task learning that leverages weak supervision provided at multiple levels of granularity by domain expert users. In MeTaL, a user specifies a problem consisting of multiple, hierarchically-related sub-tasks-for example, classifying a document at multiple levels of granularity-and then provides labeling functions for each sub-task as weak supervision. MeTaL learns a re-weighted model of these labeling functions, and uses the combined signal to train a hierarchical multi-task network which is automatically compiled from the structure of the sub-tasks. Using MeTaL on a radiology report triage task and a fine-grained news classification task, we achieve average gains of 11.2 accuracy points over a baseline supervised approach and 9.5 accuracy points over the predictions of the user-provided labeling functions.

Obesity and addiction: can a complication of surgery help us understand the connection?

Obesity is a multifactorial, chronic disease that has proven difficult to treat. An increased understanding of aetiological mechanisms is critical to the development of more effective obesity prevention and treatment strategies. A growing body of empirical evidence has demonstrated parallels between obesity, overeating and substance abuse, including shared behavioural, psychological and neurophysiological factors implicated in the excessive intake of both food and substances of abuse. Several different lines of research have recently emerged that hold the potential to shed light on the connection between obesity, food reward and addiction, with studies examining changes in alcohol use/misuse after weight loss surgery providing a particularly interesting perspective on these interrelationships. However, these lines of investigation have proceeded in relative isolation, and relevant research findings have yet to be integrated in a synthesized, comprehensive manner. To provide an opportunity to achieve such a synthesis, a scientific symposium was convened at the Radcliffe Institute in Cambridge, Massachusetts. Invited participants were researchers working in diverse domains related to the intersection between obesity and addiction. Extensive discussion was generated suggesting novel research directions. In this article, we summarize and synthesize the symposium participants' ongoing research in this area, incorporating additional relevant research holding potential clues regarding the connections between obesity, weight loss surgery and addiction.

Analysis of peptides by denaturing ultrafiltration and LC-MALDI-TOF-MS

The dynamic range of complex biological samples represents a challenge for mass spectrometric -characterization. Removal of high abundant proteins is a prerequisite for a successful mass spectrometric analysis of low abundant analytes. In particular, plasma and serum proteome span at least ten orders of magnitude and represent a major challenge for biomarker discovery. Immunoaffinity depletion is the most common methods of removal of high abundant proteins. Here we describe coupling of denaturing ultrafiltration, an alternative depletion strategy, with reverse-phase fractionation and mass spectrometry for characterization of low-molecular-weight proteins and peptides.

Robot-assisted ophthalmic surgery

Surgical robots have revolutionized a number of surgical subspecialties, including laparoscopic surgery, urology, gynecology, and orthopedics. Robots offer a number of potential improvements over unassisted human hands, such as tremor filtration, scaling of motion, enhanced dexterity in confined spaces, and extremely high precision. Several designs and prototypes have recently been introduced for use in ophthalmic surgery and they have been tested in animal models. Ophthalmic surgical robots have the potential to expand our treatment armamentarium, reduce complication rates, and hold future promise to treat surgical conditions that remain incurable today.

DNA damage phenotype and prostate cancer risk

The capacity of an individual to process DNA damage is considered a crucial factor in carcinogenesis. The comet assay is a phenotypic measure of the combined effects of sensitivity to a mutagen exposure and repair capacity. In this paper, we evaluate the association of the DNA repair kinetics, as measured by the comet assay, with prostate cancer risk. In a pilot study of 55 men with prostate cancer, 53 men without the disease, and 71 men free of cancer at biopsy, we investigated the association of DNA damage with prostate cancer risk at early (0-15 min) and later (15-45 min) stages following gamma-radiation exposure. Although residual damage within 45 min was the same for all groups (65% of DNA in comet tail disappeared), prostate cancer cases had a slower first phase (38% vs. 41%) and faster second phase (27% vs. 22%) of the repair response compared to controls. When subjects were categorized into quartiles, according to efficiency of repairing DNA damage, high repair-efficiency within the first 15 min after exposure was not associated with prostate cancer risk while higher at the 15-45 min period was associated with increased risk (OR for highest-to-lowest quartiles=3.24, 95% CI=0.98-10.66, p-trend=0.04). Despite limited sample size, our data suggest that DNA repair kinetics marginally differ between prostate cancer cases and controls. This small difference could be associated with differential responses to DNA damage among susceptible individuals.

Donepezil treatment of patients with MCI: a 48-week randomized, placebo-controlled trial

BACKGROUND

Treatment of mild cognitive impairment (MCI) with cholinesterase inhibitors may improve symptoms.

METHODS

In this multicenter, randomized, placebo-controlled trial, subjects with MCI entered a 3-week placebo run-in period followed by 48 weeks of double-blind donepezil (5 mg/day for 6 weeks, then 10 mg/day for 42 weeks) or placebo treatment. Primary efficacy variables included change from baseline in the modified Alzheimer Disease Assessment Scale-cognitive subscale (ADAS-Cog) and Clinical Dementia Rating Scale-sum of boxes (CDR-SB) after 48 weeks of treatment (modified intention-to-treat analysis). Secondary efficacy measures evaluated cognition, behavior, and function.

RESULTS

The dual primary efficacy endpoint was not reached. We noted a small, but significant, decrease in modified ADAS-Cog scores in favor of donepezil at study endpoint. Little change from baseline in CDR-SB and secondary variables was observed for either group. Patient Global Assessment scores favored donepezil at all time points except week 12 (p < or = 0.05). Perceived Deficits Questionnaire scores favored donepezil at week 24 (p = 0.05). Clinical Global Impression of Change-MCI scores favored donepezil only at week 6 (p = 0.04). Adverse events were generally mild or moderate. More donepezil-treated subjects (18.4%) discontinued treatment due to adverse events than placebo-treated subjects (8.3%).

CONCLUSIONS

Donepezil demonstrated small but significant improvement on the primary measure of cognition but there was no change on the primary measure of global function. Most other measures of global impairment, cognition, and function were not improved, possibly because these measures are insensitive to change in MCI. Responses on subjective measures suggest subjects perceived benefits with donepezil treatment.

Abstract B57: UBE3A (E6AP) auto antibodies in hepatocellular carcinoma

B57

UBE3A (E6AP) auto antibodies in hepatocellular carcinoma

1Gebreselassie, D., 1Lan, R., 1Loffredo, C.A., 2Abdel-Hamid, M., 1Goldman, R.

1Lombardi Comprehensive Cancer Center Georgetown University Washington, D.C. & 2National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt

Patients with cancer produce auto antibodies that could serve as biomarkers for detection and classification of the disease. To identify auto antibodies associated with hepatocellular carcinoma (HCC), we used a protein array of 5,000 human proteins (Invitrogen) to compare sera of ten cancer free controls and ten patients with HCC matched on age, gender, and viral infection. Thirty six proteins significantly associated with HCC (p&lt;0.05) were spotted on a custom array. The array experiments confirmed increased auto antibodies in HCC for 20 of the 36 candidates. The frequency of increase was as high as 45% for some of the auto antibodies in a comparison of 20 HCC cases and 10 matched controls. To further validate the observed auto antibody response to Ubiquitin protein ligase E3A (UBE3A), we fused cDNA for the protein, with an N-terminal FLAG tag and an enzyme reporter gene, humanized Renilla luciferase (hRluc). The construct was expressed in the Cos-1 mammalian cell line and crude cell lysates were used for quantification of auto antibodies in serum of the same individuals used in the protein array experiment. The assay is based on immunoprecipitation (IP) of the antigenic protein-construct on protein G beads followed by the quantification of hRluc chemiluminescence. Antibodies to the FLAG tag and the antigen of interest were used to optimize the assay. We found that HCC patient sera contain significantly elevated auto antibodies to UBE3A (t-test P&lt;0.01). The autoantibody response to UBE3A was observed in approximately 20% of the HCC patients and correlates with the results of the protein array experiment.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B57.

Profiling of human serum glycans associated with liver cancer and cirrhosis by IMS-MS

Aberrant glycosylation of human glycoproteins is related to various physiological states, including the onset of diseases such as cancer. Consequently, the search for glycans that could be markers of diseases or targets of therapeutic drugs has been intensive. Here, we describe a high-throughput ion mobility spectrometry/mass spectrometry analysis of N-linked glycans from human serum. Distributions of glycans are assigned according to their m/z values, while ion mobility distributions provide information about glycan conformational and isomeric composition. Statistical analysis of data from 22 apparently healthy control patients and 39 individuals with known diseases (20 with cirrhosis of the liver and 19 with liver cancer) shows that ion mobility distributions for individual m/z ions appear to be sufficient to distinguish patients with liver cancer or cirrhosis. Measurements of glycan conformational and isomeric distributions by IMS-MS may provide insight that is valuable for detecting and characterizing disease states.

In vivo pan/tilt endoscope with integrated light source, zoom and auto-focusing

We describe a surgical imaging device with pan, tilt, zoom and integrated LED light source. It can be fully inserted into the abdomen, leaving the insertion port free for tooling. Using a porcine model we have tested the device and performed surgical procedures including cholecystectomy, appendectomy, running (measuring) the bowel, suturing, and nephrectomy. The tests show that the new device is: * Easier and more intuitive to use than a standard laparoscope. * Joystick operation requires no specialized operator training. * Field of view and access to relevant regions of the body were superior to a standard laparoscope using a single port. * Time to perform procedures was better or equivalent to a standard laparoscope. We believe these insertable platforms will be an integral part of future surgical systems.

Peak selection from MALDI-TOF mass spectra using ant colony optimization

MOTIVATION

Due to the large number of peaks in mass spectra of low-molecular-weight (LMW) enriched sera, a systematic method is needed to select a parsimonious set of peaks to facilitate biomarker identification. We present computational methods for matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) spectral data preprocessing and peak selection. In particular, we propose a novel method that combines ant colony optimization (ACO) with support vector machines (SVM) to select a small set of useful peaks.

RESULTS

The proposed hybrid ACO-SVM algorithm selected a panel of eight peaks out of 228 candidate peaks from MALDI-TOF spectra of LMW enriched sera. An SVM classifier built with these peaks achieved 94% sensitivity and 100% specificity in distinguishing hepatocellular carcinoma from cirrhosis in a blind validation set of 69 samples. Area under the receiver operating characteristic (ROC) curve was 0.996. The classification capability of these peaks is compared with those selected by the SVM-recursive feature elimination method.

AVAILABILITY

Supplementary material and MATLAB scripts to implement the methods described in this article are available at http://microarray.georgetown.edu/web/files/bioinf.htm.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Efficacy of donepezil in mild cognitive impairment: a randomized placebo-controlled trial

OBJECTIVE

To evaluate the efficacy and safety of the acetylcholinesterase inhibitor donepezil in a placebo-controlled trial in patients with mild cognitive impairment (MCI).

METHODS

A total of 270 patients with MCI were enrolled in a 24-week, multicenter, randomized, double-blind, placebo-controlled study. Patients were randomized to receive donepezil (n = 133; 5 mg/day for 42 days, followed by forced dose escalation to 10 mg/day) or placebo (n = 137). Primary efficacy measures were the New York University (NYU) Paragraph Delayed Recall test and the Alzheimer disease (AD) Cooperative Study Clinician's Global Impression of Change for MCI (ADCS CGIC-MCI). Secondary efficacy measures included the modified AD Assessment Scale-cognitive subscale (ADAS-cog), the Patient Global Assessment (PGA), and additional neuropsychologic measures. Efficacy analyses were performed on intent-to-treat (ITT) and fully evaluable (FE) populations.

RESULTS

Primary efficacy measures of the NYU Paragraph Recall test and the ADCS CGIC-MCI did not show significant treatment effects in the ITT population. Some secondary measures showed effects favoring donepezil. More donepezil-treated patients showed improvements in ADAS-cog total scores, in tests of attention and psychomotor speed, and in PGA scores. More donepezil-treated than placebo-treated patients experienced adverse events, most of which were mild to moderate and transient.

CONCLUSION

Although significant treatment effects were not seen in the primary efficacy measures, outcomes on secondary measures suggest promising directions for further evaluation of donepezil treatment in patients with MCI.

Correlates of substance misuse in patients with first-episode schizophrenia and schizoaffective disorder

OBJECTIVE

To identify factors associated with substance misuse in first-episode patients with schizophrenia or schizoaffective disorder.

METHOD

Twenty-seven patients with a past or current history of substance misuse were compared with 91 patients with no history of misuse on demographic and psychopathological measures before being treated for their first episode of psychosis, and on cognitive measures after 6 months of treatment.

RESULTS

There were no statistically significant differences between groups for sex, schizophrenia subtype, marital status, education, family history of schizophrenia, course of illness, age of onset, baseline symptoms, time to treatment response, medication side effects, attention span, memory and executive functioning. However, dual diagnosis patients were found to have a higher parental social class, better premorbid cognitive functioning, higher IQ and better language skills.

CONCLUSION

First-episode patients with a history of substance misuse have higher intellectual functioning, which may be associated with higher premorbid socioeconomic status and cognitive functioning.

Smoking increases carcinogenic polycyclic aromatic hydrocarbons in human lung tissue

Tobacco smoke is a major source of human exposure to polycyclic aromatic hydrocarbons (PAHs). The concentration of PAHs in lung tissue would reflect an individual's dose, and its variation could perhaps reflect cancer risk. Eleven PAHs were measured in 70 lung tissue samples from cancer-free autopsy donors by gas chromatography-mass spectrometry. There were 37 smokers and 33 nonsmokers as estimated by serum cotinine concentration. The sum of PAH concentrations was higher in smokers (P = 0.01), and there was a dose-response relationship for greater smoking (P < 0.01). Smoking increased the concentration of five PAHs including benzo(a)pyrene, which increased approximately 2-fold. The risk for increasing carcinogenic PAHs (odds ratio, 8.20; 95% confidence interval, 2.39-28.09) was 3-fold compared with noncarcinogenic PAHs (odds ratio, 2.61; 95% confidence interval, 0.75-9.12). A higher concentration of PAHs was detected in the lung tissue of males, although the estimated smoking was similar in males and females. Race was not associated with PAH concentrations overall, but PAH concentrations appeared to be higher in African-American males than in any other group. Age was weakly correlated with an increase in fluoranthene and pyrene. The measurement of PAHs in human lung tissue can be used to estimate the actual dose to the target organ.

Human pharmacokinetic and dosimetry studies of [(18)F]FHBG: a reporter probe for imaging herpes simplex virus type-1 thymidine kinase reporter gene expression

9-[4-[(18)F]fluoro-3-(hydroxymethyl)butyl]guanine ([(18)F]FHBG) has been used as a reporter probe to image expression of herpes simplex virus type-1 thymidine kinase (HSV1-tk) reporter gene in living animals. Our aim was to study the kinetics, biodistribution, stability, dosimetry, and safety of [(18)F]FHBG in healthy human volunteers, preparatory to imaging patients undergoing HSV1-tk gene therapy.

METHODS

[(18)F]FHBG was synthesized with a specific activity of 37,000--444,000 GBq/mmol and a radiochemical purity > 99%. Ten healthy volunteers consented to participate in the study. A transmission scan was obtained before bolus injection of 70.3--229.4 MBq [(18)F]FHBG into a hand vein, followed by dynamic PET imaging with 4 consecutive emission scans. Warmed hand-vein blood was withdrawn at various times after injection for blood time--activity measurements. Electrocardiography, blood pressure, and blood and urine pharmacologic parameters were measured before and after injection of the [(18)F]FHBG tracer (n = 5). The stability of [(18)F]FHBG in the urine was analyzed. Attenuation-corrected images were reconstructed using the ordered-subsets expectation maximization algorithm. Image region-of-interest time-activity data were used with the MIRD program to estimate absorbed radiation dosages.

RESULTS

[(18)F]FHBG had rapid blood clearance; only 8.42% +/- 4.76% (mean +/- SD) of the peak blood activity remained at approximately 30 min. The average ratio of plasma activity to whole-blood activity during the study was 0.91 +/- 0.04. Penetration of [(18)F]FHBG across the blood-brain barrier was not observed. The primary routes of clearance were renal and hepatobiliary. High activities were observed in the bladder, gut, liver, and kidneys, but <0.0002% of the injected dose per gram was observed in other tissues. In the urine, 83% of activity 180 min after injection was stable [(18)F]FHBG. Blood and urine pharmacologic parameters did not change significantly after injection of the [(18)F]FHBG tracer. The bladder absorbed the highest radiation dose.

CONCLUSION

[(18)F]FHBG has the desirable in vivo characteristics of stability, rapid blood clearance, low background signal, biosafety, and acceptable radiation dosimetry in humans. This study forms the foundation for using [(18)F]FHBG in applications to monitor HSV1-tk reporter gene expression.

Trial of a novel prostacyclin analog, UT-15, in patients with severe intermittent claudication

Prostacyclin is an endothelially derived vasodilator and inhibitor of platelet aggregation. Despite its therapeutic potential for peripheral arterial disease, the short half-life and chemical instability are barriers to routine therapy. Accordingly, prostacyclin analogs are being evaluated in patients with peripheral arterial disease. State-of-the-art non-invasive ultrasonography allows for serial testing of the hemodynamic effects of vasoactive drugs. The safety, efficacy and hemodynamic effects of UT-15, a novel, long-acting prostacyclin analog, were studied in patients with severe intermittent claudication. A total of eight patients with stable severe intermittent claudication, Fontaine classes IIb-III, were admitted to the hospital for intravenous infusion of UT-15. A symptom-limited, dose-escalation protocol was instituted, beginning with placebo and then with increasing dosage at 60-min intervals, followed by a 2-h period of maintenance dose at the maximum well-tolerated infusion rate. The hemodynamic response in the lower limbs was assessed with serial ultrasonography, segmental arterial pressures and pulse volumes. Blood flow in the common femoral artery increased 29% (p = 0.003) by the end of the maintenance period and remained above baseline throughout the washout period (p = 0.044). Blood velocity in the lower limb increased in most of the peripheral arteries. These increases achieved statistical significance in the common femoral artery (p = 0.025) and anterior tibial artery (p = 0.019), and approached significance in the popliteal artery (p = 0.062). In two of four patients in whom blood flow was undetectable before the infusion, arterial blood flow at the ankle level became apparent on ultrasonography during maintenance infusion. UT-15 infusion improved the pulse volume recording (p = 0.016) but the ankle/brachial index did not change significantly. Common side effects at peak dose included headache and nausea. There were no serious adverse events attributable to UT-15 treatment. In most patients, the optimal infusion rate was 10-20 ng/kg per min. In conclusion, ultrasonography is a novel approach for assessing the hemodynamic response to vasoactive agents. UT-15 is well tolerated when given for up to 2 h and increases arterial blood flow and velocity in patients with severe intermittent claudication.