POS0689 A 6-MONTH OPEN-LABEL EXTENSION STUDY OF THE SAFETY AND EFFICACY OF INTRAVENOUS BELIMUMAB IN PATIENTS WITH LUPUS NEPHRITIS

Background:

BLISS-LN (GSK Study BEL114054; NCT01639339), the largest lupus nephritis (LN) study to date, showed that intravenous (IV) belimumab (BEL) + standard therapy (ST) improved outcomes compared with ST alone in patients (pts) with active LN.1

Objectives:

To assess additional safety and efficacy data of BEL + ST in pts with LN in a 6-month open-label (OL) phase beyond 2 years of double-blind (DB) treatment in BLISS-LN.

Methods:

In this OL phase, eligible completers of the DB phase received monthly BEL 10 mg/kg IV + ST for 6 months. Endpoints: safety; Primary Efficacy Renal Response (PERR; uPCR ≤0.7; eGFR no worse than 20% below OL baseline eGFR or ≥60 ml/min/1.73 m2; no prohibited medications) and Complete Renal Response (CRR; uPCR <0.5; eGFR no worse than 10% below OL baseline eGFR or ≥90 ml/min/1.73 m2; no prohibited medications) at OL Week 28; proportion of pts with SLEDAI score <4; corticosteroid use; biomarkers. Analyses were based on observed data and summarised relative to the OL baseline (last value measured prior to the first dose of OL treatment).

Results:

We enrolled 257 pts (57.4% of pts in BEL114054) and treated 255 pts. All treated pts were included in the safety population (123 pts switched from placebo [PBO] to BEL; 132 pts remained on BEL). Efficacy was assessed in the safety population, excluding 1 pt due to non-compliance (mITT population; PBO to BEL: 122 pts; BEL to BEL: 132 pts). 96.5% of pts completed the OL phase; 3.5% withdrew, mainly due to adverse events (AE; 2.0%).

Overall, 168/255 (65.9%) pts had ≥1 AE (76/123 [61.8%] PBO to BEL pts; 92/132 [69.7%] BEL to BEL pts); 15/255 (5.9%) pts had ≥1 serious AE (5/123 [4.1%] PBO to BEL pts; 10/132 [7.6%] BEL to BEL pts); 1 (0.8%) pt died in the PBO to BEL group.

Proportions of PERR and CRR responders increased from OL baseline to OL Week 28 (Table 1. below)

Proportions of pts who attained SLEDAI scores <4 increased from OL baseline to OL Week 28 in the BEL to BEL group and decreased in the PBO to BEL group. Among pts receiving average daily prednisone-equivalent doses of ≤5 mg or ≤7.5 mg dose was maintained from OL baseline to OL Week 28 (Table 1. below)

In pts with autoantibodies at OL baseline, anti-dsDNA and anti-C1q levels decreased from OL baseline to OL Week 28 in both groups. Among pts with low C3/C4 levels at OL baseline, C3/C4 levels increased from OL baseline to OL Week 28 in both groups (Table 1. below)

Conclusion:

In this OL phase of BLISS-LN, proportions of PERR and CRR responders increased in both the BEL-naïve and BEL-experienced groups; and no new safety signals were observed. Improvements in biomarker levels were observed, especially in pts who switched from PBO to BEL.

Funding:

GSK.

References:

[1]Furie R, et al. N Engl J Med. 2020;383(12):1117-28.

Table 1.

Responses at OL baseline and OL Week 28 (mITT population, N=254)

OL baseline*OL Week 28PBO to BEL(n=122)BEL to BEL(n=132)PBO to BEL(n=122)BEL to BEL(n=132)n122132118122PERR, n (%)73 (59.8)†93 (70.5)†79 (66.9)91 (74.6)CRR, n (%)44 (36.1)†63 (47.7)†57 (48.3)76 (62.3)SLEDAI score <4n122132120122Responders, n (%)44 (36.1)†64 (48.5)†40 (33.3)64 (52.5)Prednisone-equivalent dosen122132121128≤5 mg, n (%)59 (48.4)78 (59.1)60 (49.6)75 (58.6)≤7.5 mg, n (%)62 (50.8)85 (64.4)66 (54.5)83 (64.8)Anti-dsDNA (IU/ml)‡n85648161Median (IQR) levels107.0 (49.0, 212.0)65.5 (42.5, 126.5)--Median (IQR) % change from baseline---30.2 (-46.3, -6.8)-10.7 (-27.2, 9.1)Anti-C1q (U/ml)§n64605854Median (IQR) levels71.7 (36.6, 167.5)47.1 (33.0, 75.7)--Median (IQR) % change from baseline---23.0 (-41.5, 0.5)-16.5 (-33.0, 6.1)C3 (mg/dl)‖n45374435Median (IQR) levels78.0 (72.0, 83.0)80.0 (71.0, 84.0)--Median (IQR) % change from baseline--6.2 (-4.2, 14.6)4.7 (-4.8, 16.9)C4 (mg/dl)‖n18121811Median (IQR) levels7.5 (6.0, 8.0)7.0 (7.0, 8.5)--Median (IQR) % change from baseline--23.6 (11.1, 37.5)11.1 (0.0, 57.1)

*DB Week 104 visit and the OL baseline visit were the same visit; †Post hoc analyses; ‡Among anti-dsDNA positive pts at OL baseline (≥30 IU/ml); §Among anti-C1q positive pts at OL baseline (≥22.2 U/ml); ‖Among pts with low C3 (<90 mg/dl)/C4 (<10 mg/dl) levels at OL baseline.

Acknowledgements:

Medical writing assistance was provided by Olga Conn, PhD, Fishawack Indicia Ltd., UK, part of Fishawack Health, and was funded by GSK.

Disclosure of Interests:

Richard Furie Consultant of: GSK, Grant/research support from: GSK, Brad H Rovin Consultant of: GSK, Frederic Houssiau Consultant of: GSK, Grant/research support from: UCB, Gabriel Contreras Consultant of: Genentech, Merck, Grant/research support from: Genentech, Merck, Paula Curtis Shareholder of: GSK, Employee of: GSK, Anuradha Madan Shareholder of: GSK, Employee of: GSK, Angela Jones-Leone Shareholder of: GSK, Employee of: GSK, Mohamed Okily Shareholder of: GSK, Employee of: GSK, David Roth Shareholder of: GSK, Employee of: GSK

The gut microbiota is associated with psychiatric symptom severity and treatment outcome among individuals with serious mental illness

BACKGROUND

Emerging evidence implicates the gut microbiota in central nervous system functioning via its effects on inflammation, the hypothalamic-pituitary axis, and/or neurotransmission. Our understanding of the cellular underpinnings of the brain-gut relationship is based almost exclusively on animal models with some small-scale human studies. This study examined the relationship between the gut microbiota and psychiatric symptom severity and treatment response among inpatients with serious mental illness.

METHOD

We collected data from adult inpatients (N = 111). Measures of diagnoses, suicide severity, trauma, depression, and anxiety were collected shortly after admission, while self-collected fecal swabs were collected early in the course of hospitalization and processed using 16S rRNA gene sequencing and whole genome shotgun sequencing methods.

RESULTS

Results indicate that depression and anxiety severity shortly after admission were negatively associated with bacterial richness and alpha diversity. Additional analyses revealed a number of bacterial taxa associated with depression and anxiety severity. Gut microbiota richness and alpha diversity early in the course of hospitalization was a significant predictor of depression remission at discharge.

CONCLUSIONS

This study is among the first to demonstrate a gut microbiota relationship with symptom severity among psychiatric inpatients as well as a relationship to remission of depression post-treatment. These findings are consistent with animal models and limited human studies as well as with the broader literature implicating inflammation in the pathophysiology of depression. These findings offer the foundation for further studies of novel therapeutic approaches to the treatment, prevention of, or recurrence of serious mental illness.

Usability of daily SF36 questionnaires to capture the QALD variation experienced after vaccination with AS03A-adjuvanted monovalent influenza A (H5N1) vaccine in a safety and tolerability study

BACKGROUND

This study aims to describe the short-term reactogenicity of the AS03-adjuvanted H5N1 vaccine expressed through adverse events (AEs) and quality-adjusted life-day (QALD) scores. The AEs are likely to be short-term and therefore the quality of life (QoL) questionnaire, SF-36v2, was administered daily to record changes over seven days. A more sensitive application of this instrument should allow for a better understanding of short-term tolerability of adjuvanted vaccines.

METHODS

Participants (N = 50) received a 2-dose vaccination schedule. Solicited (collected daily: days 0 to 7 [post dose 1] and 21 to 28 [post dose 2]) and unsolicited (collected weekly until day 21) AEs were collected via diary cards. The QoL questionnaires were completed daily (days 0-6) and weekly (days 0, 6, 21, 27) after dose one. Questionnaire data were transformed into SF-6D scores to report QALDs. It was hypothesized post-hoc that the QALD and daily AEs scores should correlate if discrete QoL-changes were captured.

RESULTS

Pain (92%) and muscle ache (66%) were the most commonly reported solicited local and general AEs respectively, neither increased in intensity nor in frequency after dose 2. No safety concerns were identified during the study. A correlation between the daily AEs and QALD scores existed (correlation coefficient, - 0.97 (p < 0.001)). The impact of the AEs scores on the QALD was marginal (- 0.02 max for one day).

CONCLUSION

Similarly with other H5N1 studies, no safety concern was identified throughout the study. Some time-limited variations in QALD-scores were reported. Our results imply that daily administration of the SF-36v2 captures changes in QALD-scores.

TRIAL REGISTRATION

ClinicalTrials.gov . NCT01788228. Registered 11 February 2013.

Prospective Longitudinal Analysis of 2-Hydroxyglutarate Magnetic Resonance Spectroscopy Identifies Broad Clinical Utility for the Management of Patients With IDH-Mutant Glioma

Purpose Proton magnetic resonance spectroscopy (MRS) of the brain can detect 2-hydroxyglutarate (2HG), the oncometabolite produced in neoplasms harboring a mutation in the gene coding for isocitrate dehydrogenase ( IDH). We conducted a prospective longitudinal imaging study to determine whether quantitative assessment of 2HG by MRS could serve as a noninvasive clinical imaging biomarker for IDH-mutated gliomas. Patients and Methods 2HG MRS was performed in 136 patients using point-resolved spectroscopy at 3 T in parallel with standard clinical magnetic resonance imaging and assessment. Data were analyzed in patient cohorts representing the major phases of the glioma clinical course and were further subgrouped by histology and treatment type to evaluate 2HG. Histologic correlations were performed. Results Quantitative 2HG MRS was technically and biologically reproducible. 2HG concentration > 1 mM could be reliably detected with high confidence. During the period of indolent disease, 2HG concentration varied by less than ± 1 mM, and it increased sharply with tumor progression. 2HG concentration was positively correlated with tumor cellularity and significantly differed between high- and lower-grade gliomas. In response to cytotoxic therapy, 2HG concentration decreased rapidly in 1p/19q codeleted oligodendrogliomas and with a slower time course in astrocytomas and mixed gliomas. The magnitude and time course of the decrease in 2HG concentration and magnitude of the decrease in tumor volume did not differ between oligodendrogliomas treated with temozolomide or carmustine. Criteria for 2HG MRS were established to make a presumptive molecular diagnosis of an IDH mutation in gliomas technically unable to undergo a surgical procedure. Conclusion 2HG concentration as measured by MRS was reproducible and reliably reflected the disease state. These data provide a basis for incorporating 2HG MRS into clinical management of IDH-mutated gliomas.

Neurocognitive status is associated with all-cause mortality among psychiatric, high-risk liver transplant candidates and recipients

OBJECTIVE

Judicious selection of potential liver transplant candidates and close monitoring of progress are essential to successful outcomes. Pretransplant psychosocial evaluations are the norm, but the relationship between psychosocial (and neurocognitive status) and longer term medical outcomes is understudied. This exploratory study sought to examine the relationship between objective measures of pretransplant psychosocial and neurocognitive status and service utilization, transplant status, and all-cause mortality.

METHODS

This retrospective chart review examined outcomes among 108 psychiatric, high-risk liver transplant candidates up to four years following initial evaluation. Predictor variables of outcomes included demographic, medical, neurocognitive, psychological, and mental health treatment variables.

RESULTS

Transplant status and neurocognitive functioning were independently associated with all-cause mortality. None of the other variables were associated with outcomes.

CONCLUSIONS

Better neurocognitive functioning in high-risk liver transplant candidates may allow for greater involvement in medical care and/or compliance with treatment recommendations. More aggressive assessment and management of neurocognitive dysfunction may improve outcomes. Objective measures identified significant psychopathology typical of liver transplant candidates but were not associated with outcomes; engagement in specialized mental health care may have attenuated this relationship. Further study is needed to better understand the relationship between psychosocial functioning and outcomes.

Unusual Presentation of Necrotic Erythema Nodosum Leprosum on Scalp: A Case Report

Lepra reactions are acute episodes occurring during the disease process of leprosy and are of 2 types: type 1 or reversal reaction and type 2 reaction or erythema odosumleprosum (ENL). In the episodes of lepra reaction several parts are affected including face and extremities like oral cavity. In the present case report we reported a rare case of lepromatous leprosy with necrotic ENL involving scalp apart from the usual sites. A 58 year old married male presented to us with complaints of spontaneous onset, recurrent eruption of multiple reddish raised painful lesions. Biopsy from the infiltrated skin over the back showed atrophic epidermis, free Grenz zone, diffuse and periadnexal macrophage granulomas with predominant mononuclear infiltrate, appandageal atrophy, fibrosis around the neural structures and leukocytoclastic vasculitis. Fites stain showed strong positivity for M. leprae. His routine blood investigations showed anemia (Hb = 7.8 gm%), neutrophil leukocytosis (TLC = 17,600, DLC = P66L28M4E2) and raised ESR (80 mm in the first hour). These bullous and necrotic lesions in leprosy may be a manifestation of severe type II reactions in patients with very high bacillary load.

Measurement of regional variation of GABA in the human brain by optimized point-resolved spectroscopy at 7 T in vivo

The (1)H resonances of γ-aminobutyric acid (GABA) in the human brain in vivo are extensively overlapped with the neighboring abundant resonances of other metabolites and remain indiscernible in short-TE MRS at 7 T. Here we report that the GABA resonance at 2.28 ppm can be fully resolved by means of echo time optimization of a point-resolved spectroscopy (PRESS) scheme. Following numerical simulations and phantom validation, the subecho times of PRESS were optimized at (TE, TE2) = (31, 61) ms for detection of GABA, glutamate (Glu), glutamine (Gln), and glutathione (GSH). The in vivo feasibility of the method was tested in several brain regions in nine healthy subjects. Spectra were acquired from the medial prefrontal, left frontal, medial occipital, and left occipital brain and analyzed with LCModel. Following the gray and white matter (GM and WM) segmentation of T1 -weighted images, linear regression of metabolite estimates was performed against the fractional GM contents. The GABA concentration was estimated to be about seven times higher in GM than in WM. GABA was overall higher in frontal than in occipital brain. Glu was about twice as high in GM as in WM in both frontal and occipital brain. Gln was significantly different between frontal GM and WM while being similar between occipital GM and WM. GSH did not show significant dependence on tissue content. The signals from N-acetylaspartylglutamate were clearly resolved, giving the concentration more than 10 times higher in WM than in GM. Our data indicate that the PRESS TE = 92 ms method provides an effective means for measuring GABA and several challenging J-coupled spin metabolites in human brain at 7 T.

Proton T2 measurement and quantification of lactate in brain tumors by MRS at 3 Tesla in vivo

PURPOSE

To evaluate the T2 relaxation time of lactate (Lac) in brain tumors and the correlation of the T2 and concentration with tumor grades.

METHODS

Eight pairs of the subecho time sets of point-resolved spectroscopy were selected between 58 and 268 ms, with numerical and phantom analyses, for Lac T2 measurement. In vivo spectra were acquired from 24 subjects with gliomas (13 low grade and 11 high grade) and analyzed with LCModel using numerically-calculated basis spectra. The metabolite T2 relaxation time was obtained from monoexponential fitting of the multi-echo time (TE) signal estimates versus TE. The metabolite concentration was estimated from the zero-TE extrapolation of the T2 fits.

RESULTS

The Lac T2 was estimated to be approximately 240 ms, without a significant difference between low and high grade tumors. The Lac concentration was estimated to be 4.1 ± 3.4 and 7.0 ± 4.7 mM for low and high grades respectively, but the difference was not significant.

CONCLUSION

The Lac T2 was similar among gliomas regardless of their tumor grades. This suggests that the T2 value from this study may be applicable to obtain the T2 relaxation-free estimates of Lac in a subset of brain tumors.

In vivo detection of citrate in brain tumors by 1H magnetic resonance spectroscopy at 3T

PURPOSE

To test whether citrate is elevated in adult patients with gliomas using (1)H magnetic resonance spectroscopy (MRS) at 3T in vivo.

METHODS

Thirty-four adult patients were enrolled in the study, including six subjects with glioblastomas, eight subjects with astrocytomas (World Health Organization grade 3, n = 5; grade 2, n = 3), and 20 subjects with oligodendrogliomas (grade 3, n = 5; grade 2, n = 15). Five healthy volunteers were studied for baseline citrate data. Single-voxel localized spectra were collected with point-resolved spectroscopy (PRESS) echo times of 35 and 97 ms and were analyzed with LCModel software using numerically calculated basis spectra that included the effects of the PRESS radiofrequency and gradient pulses.

RESULTS

Citrate was not measurable by MRS in healthy brain but was detected in tumor patients at both echo times. The citrate concentration was estimated to be as high as 1.8 mM with reference to water at 42 M, with Cramér-Rao lower bounds (CRLB) as low as 5%. The mean citrate level was 0.7 ± 0.4 mM (mean ± SD, n = 32) with a median CRLB of ∼12%. No correlation was identified between citrate concentration and tumor grade or histological type.

CONCLUSION

Citrate was increased in the majority of gliomas in adult patients. The elevated citrate in our data indicates an altered metabolic state of tumor relative to healthy brain.

A comparative study of short- and long-TE ¹H MRS at 3 T for in vivo detection of 2-hydroxyglutarate in brain tumors

2-Hydroxyglutarate (2HG) is produced in gliomas with mutations of isocitrate dehydrogenase (IDH) 1 and 2. The (1) H resonances of the J-coupled spins of 2HG are extensively overlapped with signals from other metabolites. Here, we report a comparative study at 3 T of the utility of the point-resolved spectroscopy sequence with a standard short TE (35 ms) and a long TE (97 ms), which had been theoretically designed for the detection of the 2HG 2.25-ppm resonance. The performance of the methods is evaluated using data from phantoms, seven healthy volunteers and 22 subjects with IDH-mutated gliomas. The results indicate that TE = 97 ms provides higher detectability of 2HG than TE = 35 ms, and that this improved capability is gained when data are analyzed with basis spectra that include the effects of the volume localizing radiofrequency and gradient pulses.

Abstract P3-14-01: Molecular definition of the transition of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC)

Background: Ductal carcinoma in situ (DCIS) is thought to be a precursor lesion to invasive ductal carcinoma and sometimes occurs in combination with invasive disease. However, the majority of DCIS lesions do not progress to invasive disease. To date no molecular markers have been identified that associate with the potential for development to invasive disease. Our work has sought to identify molecular markers that can be used to determine the likelihood of DCIS being associated with invasive disease. Identification of such markers could be of direct therapeutic benefit, since patients with a high likelihood of associated or subsequent invasive disease could be managed more aggressively.

Methods: We have compiled matched pairs, consisting of patients that have recurred with DCIS, compared to those who have DCIS plus invasive disease. Laser-capture microdissection was used to isolate in situ and invasive components of the latter, and in situ components of the former. We analyzed these samples by parallel cDNA-mediated Annealing, Selection, Extension, and Ligation (DASL) analysis of transcription, and DNA copy number analysis by resequencing. In addition, exome capture deep re-sequencing has been conducted on multiple cored in situ versus invasive components of DCIS from the same tumor sample.

Results: Gene expression analysis revealed candidate genes that were specific to DCIS and others that were expressed only in the adjacent invasive component of the tissue. These genes are currently being evaluated to identify interesting candidates. Additionally, we characterized the gene expression signatures from tumors that recurred as DCIS only, to the DCIS component of those tumors that recurred with adjacent invasive disease. We identified genes that were differentially expressed between these data sets.

The DNA copy number analysis of laser-captured samples indicated a single dominant clone in each DCIS. In contrast to previously reported observations, the profiles of invasive versus non-invasive lesions differ significantly from one another. Observations of non-invasive versus invasive components of adjacent disease in two of the pairs indicate that the profile of the invasive lesions differ from that of the non-invasive component, however the profiles share many individual features.

Discussion: Our data identify differences between in situ and neighboring invasive tumor that may mark features associated with progression. Integration of the copy number and transcription profiling datasets will reveal the extent to which genomic alterations drive changes in gene expression. Identification of markers that distinguish indolent and aggressive subsets of DCIS that can be used to predict an association with invasive disease has the potential for near term clinical utility and may identify therapeutic targets for aggressive DCIS.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-14-01.

Beyond rose colored glasses: the adaptive role of depressive and anxious symptoms among individuals with heart failure who were evaluated for transplantation

The prospect of and the evaluative period for transplantation can be stressful for individuals with heart failure (HF). Little is known about the impact of psychosocial factors on service utilization and health outcomes. The current study examined the impact of depression, dysthymia, and anxiety on two-yr hospitalization and mortality among 96 individuals with HF who were evaluated for transplantation. Results revealed that only a small percentage of individuals endorsed sufficient symptomatology to meet criteria for a psychiatric, Axis I disorder (3.1% = anxiety; 2.1% = depression; 1.0% = dysthymia) although a significant proportion of the sample was prescribed an antidepressant or an anxiolytic (37%). Multivariable regression analysis was conducted to examine the association between significant independent demographic, medical, and psychiatric predictors and total duration of hospitalizations; logistic regression analysis was used to examine the relation between predictors and mortality. An increase in anxious symptoms was associated with a decrease in total number of days hospitalized during the two-yr period following the initial evaluation. Similarly, as depressive symptoms increased, risk of two-yr mortality decreased. Future research should assess communication between the patient and providers to further elucidate the potential relationship between psychiatric symptoms, service utilization/hospitalization, and mortality in this patient population.

Addressing narcissistic personality features in the context of medical care: integrating diverse perspectives to inform clinical practice

Narcissistic personality disorder (NPD) is characterized by an unrealistic need for admiration, lack of empathy toward others, and feelings of superiority. NPD presents a unique and significant challenge in clinical practice, particularly in medical settings with limited provider contact time, as health professionals treat individuals who often require excessive admiration and have competing treatment needs. This practice review highlights real case examples across three distinct medically oriented clinical settings (inpatient and outpatient behavioral medicine and a Level I trauma center) to demonstrate the difficult and compromising situations that providers face when treating patients with general medical conditions and comorbid narcissistic personality features. The main goal of this article is to discuss the various challenges and obstacles associated with these cases in medical settings and discuss some strategies that may prove successful. A second goal is to bridge diverse conceptualizations of narcissism/NPD through the discussion of theoretical and empirical perspectives that can inform understanding of the clinical examples. Despite differing perspectives regarding the underlying motivation of narcissistic behavior, this practice review highlights that these paradigms can be integrated when sharing the same ultimate goal: to improve delivery of care across medically oriented clinical settings for patients with narcissistic features.

Tunneling Contributions to NiP and Pin Hydrogenated Amorphous Silicon Devices

It is well known that the performance of hydrogenated amorphous silicon (a-Si) p-i-n type devices is determined by the sequence of deposition. For instance, the stainless steel/p-i-n configuration generally shows a larger value of the open circuit voltage (up to 200mV) compared to the n-i-p sequence of deposition \1,2]. Explanations of this phenomena such as the Dember potential \1], self field effect \2], residual doping \3], hydrogen effusion effects associated with the p+ layer deposition process \4, 5] are unable to satisfactorily explain the difference in performance.

Oxygenated and Fluorinated Amorphous Silicon Nitride Films and their Use in Thin Film Transistors

We present a comparison of the properties of films of amorphous silicon nitride, amorphous silicon oxynitride, and amorphous fluorinated silicon nitride deposited by plasma enhanced chemical vapor deposition. The properties of fluorinated silicon nitride films degrade when exposed to air. TFT devices fabricated with silicon nitride and silicon oxynitride insulators show thteshold voltages ≤3 V and source drain current ON/OFF ratios exceeding 107 for gate voltages smaller than 20 V, whereas TFTs with fluorinated silicon nitride insulators show an inferior performance. We also present ideas on the possible relation between the stress in the insulator film and the reliability of TFTs fabricated using these layers.

Study of a-Si:H / c-Si Heterojunctions for PV Applications

a-Si:H / c-Si heterojunction diodes were produced by PECVD with varying amorphous silicon layer thickness and hydrogen dilution of the gas phase. An accurate determination of the growth rate also in the initial stages of the deposition was made possible by an original chemical method based on the dissolution of the films followed by spectroscopical analysis of the obtained solution.

The electrical characterization of the diodes confirms the generation - recombination - multitunneling nature of the transport. Although H2 dilution is important, however, beyond a certain level it is detrimental for the junction quality, probably due to the transition to a microcrystalline phase deposition. Solar cells were also produced, the best results being an open circuit voltage of 610 mV and an intrinsic efficiency of 14.2%.

DNA methyltransferase-mediated transcriptional silencing in malignant glioma: a combined whole-genome microarray and promoter array analysis

Epigenetic inactivation of tumor suppressor genes is a common feature in human cancer. Promoter hypermethylation and histone deacetylation are reversible epigenetic mechanisms associated with transcriptional regulation. DNA methyltransferases (DNMT1 and DNMT3b) regulate and maintain promoter methylation and are overexpressed in human cancer. We performed whole-genome microarray analysis to identify genes with altered expression after RNAi-induced suppression of DNMT in a glioblastoma multiforme (GBM) cell line. We then identified genes with both decreased expression and evidence of promoter CpG island hypermethylation in GBM tissue samples using a combined whole-genome microarray transcriptome analysis in conjunction with a promoter array analysis after DNA immunoprecipitation with anti-5-methylcytidine. DNMT1 and 3b knockdown resulted in the restored expression of 308 genes that also contained promoter region hypermethylation. Of these, 43 were also found to be downregulated in GBM tissue samples. Three downregulated genes with hypermethylated promoters and restored expression in response to acute DNMT suppression were assayed for methylation changes using bisulfite sequence analysis of the promoter region after chronic DNMT suppression. Restoration of gene expression was not associated with changes in promoter region methylation, but rather with changes in histone methylation and chromatin conformation. Two of the identified genes exhibited growth suppressive activity in in vitro assays. Combining targeted genetic manipulations with comprehensive genomic and expression analyses provides a potentially powerful new approach for identifying epigenetically regulated genes in GBM.

Vascular endothelial growth factor in eye disease

Collectively, angiogenic ocular conditions represent the leading cause of irreversible vision loss in developed countries. In the US, for example, retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration are the principal causes of blindness in the infant, working age and elderly populations, respectively. Evidence suggests that vascular endothelial growth factor (VEGF), a 40kDa dimeric glycoprotein, promotes angiogenesis in each of these conditions, making it a highly significant therapeutic target. However, VEGF is pleiotropic, affecting a broad spectrum of endothelial, neuronal and glial behaviors, and confounding the validity of anti-VEGF strategies, particularly under chronic disease conditions. In fact, among other functions VEGF can influence cell proliferation, cell migration, proteolysis, cell survival and vessel permeability in a wide variety of biological contexts. This article will describe the roles played by VEGF in the pathogenesis of retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration. The potential disadvantages of inhibiting VEGF will be discussed, as will the rationales for targeting other VEGF-related modulators of angiogenesis.

In vitro metabolism of indiplon and an assessment of its drug interaction potential

This study was designed to study the in vitro metabolism of indiplon, a novel hypnotic agent, and to assess its potential to cause drug interactions. In incubations with pooled human liver microsomes, indiplon was converted to two major, pharmacologically inactive metabolites, N-desmethyl-indiplon and N-desacetyl-indiplon. The N-deacetylation reaction did not require NADPH, and appeared to be catalyzed by organophosphate-sensitive microsomal carboxylesterases. The N-demethylation of indiplon was catalyzed by CYP3A4/5 based on the following observations: (1) the sample-to-sample variation in N-demethylation of indiplon ([S] = 100 microM) in a bank of human liver microsomes was strongly correlated with testosterone 6beta-hydroxylase (CYP3A4/5) activity (r(2) = 0.98), but not with any other CYP enzyme; (2) recombinant CYP1A1, CYP1A2, CYP3A4, CYP3A5 and CYP3A7 had the ability to catalyze this reaction; (3) the N-demethylation of indiplon was inhibited by CYP3A4/5 inhibitors (ketoconazole and troleandomycin), but not by a CYP1A2 inhibitor (furafylline). In pooled human liver microsomes, indiplon exhibited a weak capacity to inhibit CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6, CYP2E1, CYP3A4/5 and carboxylesterase (p-nitrophenylacetate hydrolysis) activities (IC50 >/= 20 microM). Clinical data available on indiplon support the conclusions of this paper that the in vitro metabolism of indiplon is catalyzed by multiple enzymes, and indiplon is a weak inhibitor of human CYP enzymes.

Neurologic events in neonates treated surgically for congenital heart disease

OBJECTIVE

The incidence of acute neurologic events prior to discharge in neonates with congenital heart disease (CHD) was determined and peri-operative characteristics predictive of a neurologic event were identified.

STUDY DESIGN

A retrospective chart review over 1 year was conducted of infants <1 month of age with a diagnosis of CHD. Outcomes were measured by the occurrence of an acute neurologic event defined as electroencephalogram (EEG)-proven seizure activity, significant hypertonia or hypotonia, or choreoathetosis prior to hospital discharge. Stepwise logistic regression identified variables most likely to be associated with an acute neurologic event.

RESULTS

Surgical intervention occurred in 95 infants who were admitted with a diagnosis of CHD. The survival rate was 92%. Of the survivors, 16 (17%) had an acute neurologic event, with 19% of events occurring preoperatively. Factors associated with neurologic events included an elevated nucleated red blood cell (NRBC) count, an abnormal preoperative brain imaging study, and a 5-min Apgar score <7 (P<0.05).

CONCLUSIONS

Neonates with CHD have a significant risk of neurologic events. Preoperative brain imaging, the 5-min Apgar score, and initial serum NRBC counts may identify infants at highest risk for central nervous system injury.

Despite high satisfaction, majority of gastro-oesophageal reflux disease patients continue to use proton pump inhibitors after antireflux surgery

BACKGROUND

While antireflux surgery is effective in controlling symptoms of gastro-oesophageal reflux, its role in eliminating the use of antireflux medicines after surgery and as such its long-term cost-effectiveness remains controversial.

AIM

To assess the patient satisfaction and the continued medication use following laparoscopic Nissen fundoplication at a tertiary level community hospital.

METHODS

Adult patients who underwent laparoscopic Nissen fundoplication at our institution over a period of over 3 years were asked to complete a questionnaire recording their demographic information, date and reason for the surgery, preprocedure and postprocedure symptoms, smoking and alcohol use, and medication use preoperatively and post-operatively. Patients were also asked about their satisfaction with surgery.

RESULTS

One hundred patients participated in the study. Overall, 90% patients experienced satisfaction with their surgery. Eighty percentage patients were willing to undergo surgery again, if needed. Over two-thirds (67%) patients had decrease in the severity of their symptoms. None of the patients had worsening of symptoms post-operatively. However, 80% patients were still taking antireflux medications including proton pump inhibitors (53%).

CONCLUSIONS

Most patients continue to use antireflux medications including after laparoscopic Nissen fundoplication despite high satisfaction with surgery.

Embolization for major lower gastrointestinal haemorrhage: five-year experience

The management of major lower gastrointestinal haemorrhage has changed dramatically in the last 15 years. Innovations in coaxial catheter technology have allowed the interventional radiologist to reach the small peripheral mesenteric arteries and perform superselective embolization with a variety of agents. The present large series represents the 5-year experience of this technique at the Alfred Hospital, Melbourne, in a patient cohort with a high number of comorbidities. Technical success was achieved in 96% of cases. The clinical symptoms of mesenteric ischaemia developed in four patients after embolization and were managed conservatively in two. The procedure-related mortality was low when compared with the published complication rates for emergency surgery, in this clinical setting.

Incidence of various causes of vaginal discharge among sexually active females in age group 20-40 years

The present study was undertaken to know incidence of various causes of vaginal discharge in sexually active females of age group 20-40 years. One hundred sexually active females in the age group of 20-40 years, with vaginal discharge, were selected for this study at random. A detailed clinical history and a thorough examination of all the cases was done. After making the clinical diagnosis, appropriate tests for diagnosing candidiasis, trichomoniasis, gonorrhoea and bacterial vaginosis were done. The present study showed 45% incidence of bacterial vaginosis, 31% vulvovaginal candidiasis, 2% trichomoniasis, 3% gonorrhoea, 5% non-specific urogenital causes, and 14% with other causes.

Evaluation of causes of vaginal discharge in relation to pregnancy status

The purpose of this study was to determine incidence of vaginal discharge in pregnant and non-pregnant sexually active females of age group 20-40 years presenting with the chief complaint of vaginal discharge. One hundred sexually active females in the age group of 20-40 years, with vaginal discharge, were selected for this study at random. A detailed clinical history and a thorough examination of all the cases were done. After making the clinical diagnosis, appropriate tests for diagnosing candidiasis, trichomoniasis, gonorrhoea and bacterial vaginosis were done. It was observed that out of 100 cases, 13 (13%) patients were pregnant and 87 (87%) were non-pregnant.

Autocrine stimulation by erythropoietin in transgenic mice results in erythroid proliferation without neoplastic transformation

Erythropoietin (Epo) autocrine stimulation has been implicated in erythroleukemia. To develop a model of Epo autocrine stimulation, we made transgenic mice using a construct that linked the human Epo gene to an erythroid-specific regulatory element, designated 5'HS-2, from the human beta-globin locus control region. We hypothesized that Epo gene expression would be targeted to erythroid cells in these mice, resulting in autocrine stimulation of erythroid progenitor cell growth in culture, and that chronic autocrine Epo stimulation would result in erythroleukemia. Transgenic mice containing intact copies of the 5'HS-2Epo construction had elevated hematocrits, reticulocyte counts and serum Epo levels and marked splenic enlargement. Analysis of RNA isolated from organs of transgenic mice revealed constitutive Epo mRNA expression primarily in spleen, blood and bone marrow. RNA samples from anemic transgenic mice revealed Epo gene induction only in the liver. Marrow derived from 5'HS-2Epo mice grew BFU-E in the absence of exogenous Epo. Despite observation of up to 2 years, no mouse developed erythroleukemia, demonstrating that Epo autocrine stimulation alone is insufficient for progression to malignancy. These studies show that 5'HS-2 can be used to target Epo gene expression to erythroid tissue. These mice could provide a model system for studying autocrine growth regulation.

Subcutaneous epinephrine vs nebulized salbutamol in asthma

OBJECTIVE

This study was conducted to compare the efficacy of the subcutaneous epinephrine with nebulized salbutamol.

METHODS

Fifty asthmatic children in the age range of 6-14 years were divided into two equal groups. Group I children were given subcutaneous epinephrine and Group II were nebulized with salbutamol. Patients were observed at 15, 20, 30, 60, 120, 180 and 240 minute intervals. Both the groups had comparable mean increase in peak expiratory flow rate (PEFR %) (Group I 27.7 +/- 0.7; Group II 28.8 +/- 0.06, p >0.05).

RESULT

In Group I there was significant increase in systolic blood pressure, 30 minutes after the start of treatment, however it settled on its own by 60 minutes.

CONCLUSION

Both the groups had satisfactory improvement in clinical parameters which continued upto 4 hours after start of treatment. Subcutaneous epinephrine can be safely used if nebulizers are not available.

Limb/pelvis hypoplasia/aplasia with skull defect (Schinzel phocomelia): distinctive features and prenatal detection

Schinzel phocomelia syndrome is characterized by limb/pelvis hypoplasia/aplasia: specifically, intercalary limb deficiencies and absent or hypoplastic pelvic bones. The phenotype is similar to that described in a related multiple malformation syndrome known as Al-Awadi/Raas-Rothschild syndrome. The additional important feature of large parietooccipital skull defects without meningocele, encephalocele, or other brain malformation has thus far been reported only in children with Schinzel phocomelia syndrome. We recently evaluated a boy affected with Schinzel phocomelia born to nonconsanguineous healthy parents of Mexican origin. A third-trimester fetal ultrasound scan showed severe limb deficiencies and an absent pelvis. The infant died shortly after birth. Dysmorphology examination, radiographs, and autopsy revealed quadrilateral intercalary limb deficiencies with preaxial toe polydactyly; an absent pelvis and a 7 x 3-cm skull defect; and extraskeletal anomalies including microtia, telecanthus, micropenis with cryptorchidism, renal cysts, stenosis of the colon, and a cleft alveolar ridge. A normal 46,XY karyotype was demonstrated, and autosomal recessive inheritance was presumed on the basis of previously reported families. This case report emphasizes the importance of recognizing severe pelvic and skull deficiencies (either post- or prenatally) in differentiating infants with Schinzel phocomelia from other multiple malformation syndromes that feature intercalary limb defects, including thalidomide embryopathy and Roberts-SC phocomelia.

Congenital hypomyelination neuropathy in a newborn infant: unusual cause of diaphragmatic and vocal cord paralyses

We report a case of congenital hypomyelination neuropathy presenting at birth. The infant had generalized hypotonia and weakness. There was decreased respiratory effort along with a right phrenic nerve and left vocal cord paralyses. Tongue fasciculations were present. Deep tendon reflexes were absent in the upper extremities and hypoactive (1+) in the lower extremities. Magnetic resonance imaging of the head revealed no intracranial abnormalities, including normal cerebral myelination. Nerve conduction study showed absence of motor and sensory action potentials in the hands when the nerves in the upper limbs were stimulated. A motor response could be elicited only in the proximal leg muscles. Needle electromyography study was normal in the proximal limb muscles, but showed active denervation in the distal muscles of the arm and leg. These findings were thought to be consistent with a length-dependent sensorimotor peripheral polyneuropathy of axonal type with greater denervation of the distal muscles. A biopsy of the quadriceps muscle showed mild variability in fiber diameter, but no group typing or group atrophy. The muscle fibers showed no intrinsic abnormalities. Biopsy of the sural nerve showed scattered axons with very thin myelin sheaths. There was also a nearly complete loss of large diameter myelinated fibers. No onion bulb formations were noted. These findings were thought to be consistent with congenital hypomyelination neuropathy with a component of axonopathy. DNA analysis for identification of previously characterized mutations in the genes MPZ, PMP22, and EGR2 was negative. Several attempts at extubation failed and the infant became increasingly ventilator-dependent with increasing episodes of desaturation and hypercapnea. He also developed increasing weakness and decreased movement of all extremities. He underwent surgery at 2 months of age for placement of a gastrostomy tube and a tracheostomy. He was discharged from the hospital on a ventilator at 6 months of age. The infant was 13 months old at the time of submission of this report. Although he appears cognitively normal, he remains profoundly hypotonic and is on a home ventilator. There was no evidence of progressive weakness. Congenital hypomyelination neuropathy is a rare form of neonatal neuropathy that should be considered in the differential diagnosis of a newborn with profound hypotonia and weakness. It appears to be a heterogeneous disorder with some of the cases being caused by specific genetic mutations.

Coordinate regulation of xenobiotic and bile acid homeostasis by pregnane X receptor

Identification and characterization of the pregnane X receptor (PXR) as a key regulator of cytochrome P450 3A (CYP3A) gene expression has led to an increased understanding of the molecular basis of many drug-drug interactions. Mice lacking PXR (PXR-KO) were used in the present study to delineate the role of PXR in regulating hepatomegaly and regulating the activity of CYP3A, organic anion transporting polypeptide-2 (Oatp2), and Cyp7a1 (cholesterol 7alpha-hydroxylase) gene products in vivo. Pregnenolone-16alpha-carbonitrile (PCN) produced hepatomegaly in the wild-type mice but not in the PXR-KO mice. PCN increased both the number of proliferating cell nuclear antigen immuno-positive nuclei and apparent cell size in the wild-type mice but not in the PXR-KO mice. To determine the role PXR plays in regulating CYP3A activity, 6beta-hydroxylation of testosterone and the duration of the loss of righting reflex following administration of the muscle-relaxant zoxazolamine were measured. PCN increased the level of testosterone 6beta-hydroxylation and decreased the duration of the loss of righting-reflex time following zoxazolamine administration in wild-type mice, but did not effect either of these parameters in PXR-KO mice. PCN increased the hepatic uptake of [(3)H]digoxin, an Oatp2 substrate, in wild-type mice but not in the PXR-KO mice. Similarly, PCN decreased bile acid excretion in wild-type mice but not in the PXR-KO mice. Taken together, these data demonstrate a pivotal role for PXR in the regulation of drug-induced hepatomegaly and in the metabolism (CYP3A), transport (Oatp2), biosynthesis (Cyp7a1), and excretion of xenobiotics and bile acids in vivo.

Drugs, guns, and kids: the association between substance use and injury caused by interpersonal violence

BACKGROUND

Drug and alcohol uses have been linked to the frequency of injury events, recurrent hospital admission for injury, and interpersonal violence. Data regarding the association of recent substance use and injury type and frequency in children and young adults are not available. Such data probably would be valuable in planning interventions to prevent substance use and reduce the risks of injuries.

METHODS

Evidence of substance use was assessed in trauma patients presenting to the authors' level 1 trauma center over a 6-month interval. Demographic data, mechanisms of injury, revised trauma scores (RTS), injury severity scores (ISS), hospital days, and mortality rate were evaluated. Chi square analysis and 2-tailed, paired t tests were used for statistical analysis. Multivariate logistic regression was utilized to determine the influence of individual variables.

RESULTS

From a total group of 743 patients with life-threatening injuries, trauma registry records of 186 patients less than 21 years old were eligible for evaluation, and 126 of these had complete blood and urine drug assessments completed on admission to the trauma center. Forty-two percent (53 of 126) patients tested positive for alcohol or drugs. No patients less than 14 years of age (n = 61) had positive drug screen results. However, in the cohort of patients aged 14 and 15 (n = 17), 71% tested positive. Also, 72% of adolescents (age < 18) who were victims of injuries from gunshot wounds had evidence of substance use. Multivariate analysis showed gunshot wounds (P <.003) to be associated independently with positive drug screens. No statistical differences were observed in ethnic distribution, ISS, RTS, hospital days, or mortality rate when patients with positive screen results were compared with those without evidence of substance use.

CONCLUSIONS

Trauma victims had evidence of substance use in early teen age years especially in the 14 and 15-year-old age groups. Toxicology screening disclosed that substance use is associated strongly with gunshot wounds. Substance use, along with poverty, inadequate family support, and peer pressure are factors that influence injury risk. Interventions to prevent substance use in young children may reduce the risk of injury.

Initial sequencing and analysis of the human genome

The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

A physical map of the human genome

The human genome is by far the largest genome to be sequenced, and its size and complexity present many challenges for sequence assembly. The International Human Genome Sequencing Consortium constructed a map of the whole genome to enable the selection of clones for sequencing and for the accurate assembly of the genome sequence. Here we report the construction of the whole-genome bacterial artificial chromosome (BAC) map and its integration with previous landmark maps and information from mapping efforts focused on specific chromosomal regions. We also describe the integration of sequence data with the map.

Imaging of frontal sinus disease: concepts, interpretation, and technology

Imaging of the frontal sinus is an integral part of patient evaluation. High-resolution computed tomography (CT) imaging is the preferred modality for evaluation of sinus inflammatory disease. Magnetic resonance (MR) imaging plays an important role in differentiating tumors from inflammatory diseases and serves as a problem-solving tool.

Biotransformation of the anti-angiogenic compound SU5416

SU5416 [3-(3,5-dimethyl-1H-pyrrol-2-ylmethylene)-1, 3-dihydro-indol-2-one], an inhibitor of VEGF (vascular endothelial growth factor) receptor tyrosine kinase, Flk-1/KDR (fetal liver kinase 1/kinase insert domain-containing receptor), also known as VEGF receptor 2 (VEGFR2) is in advanced clinical trials for treatment of AIDS-related Kaposi's sarcoma and colorectal and nonsmall cell lung cancers. Since this chemical class has not been studied previously with therapeutic intent, the present study was designed to investigate the in vitro metabolism of SU5416 by mouse, rat, dog, monkey, and human liver microsomes and to identify the major metabolites of SU5416. An HPLC procedure was developed and validated to resolve and quantify SU5416 and its metabolites. To evaluate the in vitro metabolism of SU5416, pooled liver microsomes from mice, rats, dogs, monkeys, and humans were incubated with SU5416 (25 microM) in the presence of an NADPH-generating system. In the presence of NADPH, mouse, rat, dog, monkey, and human liver microsomes converted SU5416 to at least 12, 9, 9, 7, and 6 polar metabolites, respectively. Microsomal metabolism of SU5416 showed marked species differences in the levels of different metabolites formed. The overall rate of SU5416 metabolism by liver microsomes from the species examined followed the rank order: monkey > or = mouse approximately rat > dog > human. Two major metabolites of SU5416 were identified, a hydroxymethyl derivative of SU5416 (M12) and a carboxylic acid derivative of SU5416 (M6), by spectroscopic methods and comparison with authentic compounds. Both of these oxidative metabolites were further metabolized in vivo through glucuronidation. The metabolic fate of SU5416 in microsomes from various species as well as data from in vivo biotransformation in the rat are discussed.

Testing the hypothesis of a recombinant origin of human immunodeficiency virus type 1 subtype E

The human immunodeficiency virus type 1 (HIV-1) epidemic in Southeast Asia has been largely due to the emergence of clade E (HIV-1E). It has been suggested that HIV-1E is derived from a recombinant lineage of subtype A (HIV-1A) and subtype E, with multiple breakpoints along the E genome. We obtained complete genome sequences of clade E viruses from Thailand (93TH057 and 93TH065) and from the Central African Republic (90CF11697 and 90CF4071), increasing the total number of HIV-1E complete genome sequences available to seven. Phylogenetic analysis of complete genomes showed that subtypes A and E are themselves monophyletic, although together they also form a larger monophyletic group. The apparent phylogenetic incongruence at different regions of the genome that was previously taken as evidence of recombination is shown to be not statistically significant. Furthermore, simulations indicate that bootscanning and pairwise distance results, previously used as evidence for recombination, can be misleading, particularly when there are differences in substitution or evolutionary rates across the genomes of different subtypes. Taken jointly, our analyses suggest that there is inadequate support for the hypothesis that subtype E variants are derived from a recombinant lineage. In contrast, many other HIV strains claimed to have a recombinant origin, including viruses for which only a single parental strain was employed for analysis, do indeed satisfy the statistical criteria we propose. Thus, while intersubtype recombinant HIV strains are indeed circulating, the criteria for assigning a recombinant origin to viral structures should include statistical testing of alternative hypotheses to avoid inappropriate assignments that would obscure the true evolutionary properties of these viruses.

Expression and regulation of cytochrome P450 enzymes in primary cultures of human hepatocytes

The aim of this study was to test suitable culture conditions for maintaining normal cellular cytoarchitecture and inducibility of P450 enzymes in primary cultures of human hepatocytes by prototypical inducers. The selectivity and sensitivity of a sandwich culture system were determined by treating cultures with a number of clinically relevant drugs that are known to be inducers of either rodent and/or human P450 enzymes. The results showed that considerable induction of CYP3A4 activity is observed at DMSO concentrations greater than 0.1% (v/v). No differences in P450 induction response were observed between cultures maintained under different matrix conditions. However, the matrix condition considered to be optimal for maintaining cellular integrity, protein yields, and P450 enzyme induction was a sandwich configuration in combination with modified Chee's medium containing insulin (6.25 microg/mL) and dexamethasone (< or =0.1 microM). Under these conditions, induction of CYP3A4 occurred at clinically relevant drug concentrations, and maximal activities were achieved after 3 days of exposure. Overall, the response of human hepatocyte cultures to treatment with both positive and negative modulators was found to reflect that observed in vivo with respect to both enzyme specificity and potency of enzyme induction, although considerable sample-to-sample variability was observed in the magnitude of induction.

In vitro inhibition and induction of human hepatic cytochrome P450 enzymes by modafinil

The ability of modafinil to affect human hepatic cytochrome P450 (CYP) activities was examined in vitro. The potential for inhibition of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4/5, and CYP4A9/11 by modafinil (5-250 microM) was evaluated with pooled human liver microsomes. Modafinil exhibited minimal capacity to inhibit any CYP enzyme, except CYP2C19. Modafinil inhibited the 4'-hydroxylation of S-mephenytoin, a marker substrate for CYP2C19, reversibly and competitively with a K(i) value of 39 microM, which approximates the steady-state C(max) value of modafinil in human plasma at a dosage of 400 mg/day. No irreversible inhibition of any CYP enzyme was observed, and there was no evidence of metabolism-dependent inhibition. The potential for induction of CYP activity was evaluated by exposing primary cultures of human hepatocytes to modafinil (10-300 microM). Microsomes were then prepared and assayed for CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5 activities. The mean activities of microsomal CYP1A2, CYP2B6, and CYP3A4/5 from modafinil-treated hepatocytes were higher (up to 2-fold) than those in the solvent-treated controls but were less than those produced by reference inducers of these enzymes. At high concentrations of modafinil (>/=100 microM), the mean activity of CYP2C9 was decreased (up to 60%) relative to that in the solvent controls. Overall, modafinil was shown to have effects on human hepatic CYP1A2, CYP2B6, CYP2C9, CYP2C19, and CYP3A4/5 activities in vitro. Although effects obtained in vitro are not always predictive of effects in vivo, such results provide a rational basis for understanding drug-drug interactions that are observed clinically and for planning subsequent investigations.