First-line erlotinib versus gemcitabine/cisplatin in patients with advanced EGFR mutation-positive non-small-cell lung cancer: analyses from the phase III, randomized, open-label, ENSURE study

BACKGROUND

The phase III, randomized, open-label ENSURE study (NCT01342965) evaluated first-line erlotinib versus gemcitabine/cisplatin (GP) in patients from China, Malaysia and the Philippines with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients ≥18 years old with histologically/cytologically confirmed stage IIIB/IV EGFR mutation-positive NSCLC and Eastern Cooperative Oncology Group performance status 0-2 were randomized 1:1 to receive erlotinib (oral; 150 mg once daily until progression/unacceptable toxicity) or GP [G 1250 mg/m(2) i.v. days 1 and 8 (3-weekly cycle); P 75 mg/m(2) i.v. day 1, (3-weekly cycle) for up to four cycles]. Primary end point: investigator-assessed progression-free survival (PFS). Other end points include objective response rate (ORR), overall survival (OS), and safety.

RESULTS

A total of 217 patients were randomized: 110 to erlotinib and 107 to GP. Investigator-assessed median PFS was 11.0 months versus 5.5 months, erlotinib versus GP, respectively [hazard ratio (HR), 0.34, 95% confidence interval (CI) 0.22-0.51; log-rank P < 0.0001]. Independent Review Committee-assessed median PFS was consistent (HR, 0.42). Median OS was 26.3 versus 25.5 months, erlotinib versus GP, respectively (HR, 0.91, 95% CI 0.63-1.31; log-rank P = .607). ORR was 62.7% for erlotinib and 33.6% for GP. Treatment-related serious adverse events (AEs) occurred in 2.7% versus 10.6% of erlotinib and GP patients, respectively. The most common grade ≥3 AEs were rash (6.4%) with erlotinib, and neutropenia (25.0%), leukopenia (14.4%), and anemia (12.5%) with GP.

CONCLUSION

These analyses demonstrate that first-line erlotinib provides a statistically significant improvement in PFS versus GP in Asian patients with EGFR mutation-positive NSCLC (NCT01342965).

Afatinib versus gefitinib in patients with EGFR mutation-positive advanced non-small-cell lung cancer: overall survival data from the phase IIb LUX-Lung 7 trial

Background

In LUX-Lung 7, the irreversible ErbB family blocker, afatinib, significantly improved progression-free survival (PFS), time-to-treatment failure (TTF) and objective response rate (ORR) versus gefitinib in patients with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). Here, we present primary analysis of mature overall survival (OS) data.

Patients and methods

LUX-Lung 7 assessed afatinib 40 mg/day versus gefitinib 250 mg/day in treatment-naïve patients with stage IIIb/IV NSCLC and a common EGFR mutation (exon 19 deletion/L858R). Primary OS analysis was planned after ∼213 OS events and ≥32-month follow-up. OS was analysed by a Cox proportional hazards model, stratified by EGFR mutation type and baseline brain metastases.

Results

Two-hundred and twenty-six OS events had occurred at the data cut-off (8 April 2016). After a median follow-up of 42.6 months, median OS (afatinib versus gefitinib) was 27.9 versus 24.5 months [hazard ratio (HR) = 0.86, 95% confidence interval (CI) 0.66‒1.12, P = 0.2580]. Prespecified subgroup analyses showed similar OS trends (afatinib versus gefitinib) in patients with exon 19 deletion (30.7 versus 26.4 months; HR, 0.83, 95% CI 0.58‒1.17, P = 0.2841) and L858R (25.0 versus 21.2 months; HR 0.91, 95% CI 0.62‒1.36, P = 0.6585) mutations. Most patients (afatinib, 72.6%; gefitinib, 76.8%) had at least one subsequent systemic anti-cancer treatment following discontinuation of afatinib/gefitinib; 20 (13.7%) and 23 (15.2%) patients received a third-generation EGFR tyrosine kinase inhibitor. Updated PFS (independent review), TTF and ORR data were significantly improved with afatinib.

Conclusion

In LUX-Lung 7, there was no significant difference in OS with afatinib versus gefitinib. Updated PFS (independent review), TTF and ORR data were significantly improved with afatinib.

Clinicaltrials.gov identifier

NCT01466660.

Final overall survival results from a randomised, phase III study of erlotinib versus chemotherapy as first-line treatment of EGFR mutation-positive advanced non-small-cell lung cancer (OPTIMAL, CTONG-0802)

BACKGROUND

The OPTIMAL study was the first study to compare efficacy and tolerability of the epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) erlotinib, versus standard chemotherapy in first-line treatment of patients with EGFR mutation-positive advanced non-small-cell lung cancer (NSCLC). Findings from final overall survival (OS) analysis and assessment of post-study treatment impact are presented.

PATIENTS AND METHODS

Of 165 randomised patients, 82 received erlotinib and 72 gemcitabine plus carboplatin. Final OS analyses were conducted when 70% of deaths had occurred in the intent-to-treat population. Subgroup OS was analysed by Cox proportional hazards model and included randomisation stratification factors and post-study treatments.

RESULTS

Median OS was similar between the erlotinib (22.8 months) and chemotherapy (27.2 months) arms with no significant between-group differences in the overall population [hazard ratio (HR), 1.19; 95% confidence interval (CI) 0.83-1.71; P = 0.2663], the exon 19 deletion subpopulation (HR, 1.52; 95% CI 0.91-2.52; P = 0.1037) or the exon 21 L858 mutation subpopulation (HR, 0.92; 95% CI 0.55-1.54; P = 0.7392). More patients in the erlotinib arm versus the chemotherapy arm did not receive any post-study treatment (36.6% versus 22.2%). Patients who received sequential combination of EGFR-TKI and chemotherapy had significantly improved OS compared with those who received EGFR-TKI or chemotherapy only (29.7 versus 20.7 or 11.2 months, respectively; P < 0.0001). OS was significantly shorter in patients who did not receive post-study treatments compared with those who received subsequent treatments in both arms.

CONCLUSION

The significant OS benefit observed in patients treated with EGFR-TKI emphasises its contribution to improving survival of EGFR mutant NSCLC patients, suggesting that erlotinib should be considered standard first-line treatment of EGFR mutant patients and EGFR-TKI treatment following first-line therapy also brings significant benefits to those patients.

CLINICALTRIALSGOV IDENTIFIER

NCT00874419.

Neutralizing antibody-independent containment of immunodeficiency virus challenges by DNA priming and recombinant pox virus booster immunizations

Eight different protocols were compared for their ability to raise protection against immunodeficiency virus challenges in rhesus macaques. The most promising containment of challenge infections was achieved by intradermal DNA priming followed by recombinant fowl pox virus booster immunizations. This containment did not require neutralizing antibody and was active for a series of challenges ending with a highly virulent virus with a primary isolate envelope heterologous to the immunizing strain.

Cytokine production at the site of disease in human tuberculosis

Clinical and immunologic evidence suggests that tuberculous pleuritis provides a model to understand protective immune mechanisms against Mycobacterium tuberculosis. We therefore evaluated the pattern of cytokine mRNA expression and cytokine production in pleural fluid and blood of patients with tuberculous pleuritis. RNA was extracted from mononuclear cells, reverse transcribed to cDNA, and amplified by polymerase chain reaction (PCR). After normalization for T-cell cDNA, cDNA from pleural fluid cells and peripheral blood mononuclear cells (PBMC) was amplified with cytokine-specific primers. PCR product was quantified by Southern blot. For the Th1 cytokines gamma interferon (IFN-gamma) and interleukin-2 (IL-2), PCR product was greater in pleural fluid than in blood, whereas PCR product for the Th2 cytokine IL-4 was decreased in pleural fluid compared with blood. Concentrations of IFN-gamma were elevated in pleural fluid compared with serum, but IL-2, IL-4, and IL-5 were not detectable. Mean concentrations of IFN-gamma and IL-2 in supernatants of M. tuberculosis-stimulated pleural fluid cells were significantly greater than corresponding concentrations in supernatants of stimulated PBMC. In situ hybridization showed that increased IFN-gamma production by pleural fluid cells was associated with a 20- to 60-fold increase in the frequency of antigen-reactive IFN-gamma-mRNA-expressing cells. Because IL-10 can be produced by T cells and macrophages, pleural fluid cells and PBMC were normalized for beta-actin cDNA content and then amplified by PCR with IL-10-specific primers. IL-10 mRNA was greater in pleural fluid cells than in PBMC and was expressed predominantly by macrophages. IL-10 concentrations were elevated in pleural fluid versus serum. These data provide strong evidence for compartmentalization of Th1 cytokines and IL-10 at the site of disease in humans with a resistant immune response to mycobacterial infection.

Plasma very long chain fatty acids in 3,000 peroxisome disease patients and 29,000 controls

The assay of plasma very long chain fatty acids (VLCFAs), developed in our laboratory in 1981, has become the most widely used procedure for the diagnosis of X-linked adrenoleukodystrophy (X-ALD) and other peroxisomal disorders. We present here our 17 years' experience with this assay. Three VLCFA parameters, the level of hexacosanoic acid (C26:0), the ratio of C26:0 to tetracosanoic acid (C24:0), and of C26:0 to docosanoic acid (C22:0), were measured in 1,097 males (hemizygotes) with X-ALD, 1,282 women heterozygous for this disorder, including 379 obligate heterozygotes, 797 patients with other peroxisomal disorders, and 29,600 control subjects. All X-ALD hemizygotes who had not previously received Lorenzo's oil or a diet with a high erucic acid content had increased VLCFA levels, but the application of a discriminant function based on all three measurements is required to avoid the serious consequences of a false-negative result. VLCFA levels are increased at day of birth, thus providing the potential for neonatal mass screening, are identical in the childhood and adult forms, and do not change with age. Eighty-five percent of obligate heterozygotes had abnormally high VLCFA levels, but a normal result does not exclude carrier status. VLCFA levels were increased in all patients homozygous for Zellweger syndrome, neonatal adrenoleukodystrophy, infantile Refsum's disease, and in patients with deficiencies of peroxisomal acyl-coenzyme A oxidase, bifunctional enzyme, and 3-oxoacyl-coenzyme A thiolase. In these patients the degree of VLCFA excess correlated with clinical severity.

Concomitant montelukast and loratadine as treatment for seasonal allergic rhinitis: a randomized, placebo-controlled clinical trial

BACKGROUND

Nasal challenge studies have suggested histamine and cysteinyl leukotrienes are important proinflammatory mediators in allergic rhinitis. This study was designed to determine the efficacy of montelukast, a cysteinyl leukotriene receptor antagonist, administered alone or concomitantly with loratadine, an H(1)-receptor antagonist, in seasonal allergic rhinitis.

OBJECTIVE

The purpose of this study was to determine the effect of concomitant use of montelukast and loratadine in the treatment of seasonal allergic rhinitis.

METHODS

In this multicenter (N = 12) double-blind, randomized, parallel-group, placebo-controlled 2-week trial, 460 men and women, aged 15 to 75 years, with spring seasonal allergic rhinitis were randomly allocated to receive 1 of the following 5 treatments: montelukast 10 or 20 mg, loratadine 10 mg, montelukast 10 mg with loratadine 10 mg, or placebo, once daily in the evening. The primary end point was daytime nasal symptoms score (average of congestion, rhinorrhea, itching, and sneezing). Other end points were eye symptoms, nighttime symptoms, individual daytime nasal symptoms, global evaluations (patient's and physician's), and rhinoconjunctivitis quality-of-life scores.

RESULTS

Concomitant montelukast with loratadine improved the primary end point significantly (P <.001) compared with placebo and each agent alone. Compared with placebo, montelukast with loratadine also significantly improved eye symptoms, nighttime symptoms, individual daytime nasal symptoms, global evaluations, and quality of life. Montelukast alone and loratadine alone caused modest improvements in rhinitis end points. All treatments were similarly well tolerated.

CONCLUSIONS

Concomitant montelukast with loratadine provided effective treatment for seasonal allergic rhinitis and associated eye symptoms with a safety profile comparable with placebo.

Montelukast added to inhaled beclomethasone in treatment of asthma. Montelukast/Beclomethasone Additivity Group

The primary objective of this study was to determine whether montelukast, an oral leukotriene receptor antagonist, provides additional clinical benefit to the effect of inhaled corticosteroids. A total of 642 patients with chronic asthma (FEV(1) 50 to 85% of predicted value and at least a predefined level of asthma symptoms) incompletely controlled with inhaled beclomethasone, 200 microg twice daily using a spacer device, during the 4-wk run-in period were randomly allocated, in a double-blind, double-dummy manner to one of four treatment groups: (1) montelukast 10 mg plus continuing inhaled beclomethasone; (2) placebo tablet plus continuing inhaled beclomethasone; (3) montelukast 10 mg and inhaled placebo (after blind beclomethasone removal); and (4) placebo tablet and inhaled placebo (after blind beclomethasone removal). The primary endpoints were FEV(1) and daytime asthma symptoms score. Montelukast provided significant (p < 0.05) clinical benefit in addition to inhaled beclomethasone by improving FEV(1), daytime asthma symptom scores, and nocturnal awakenings. Blind removal of beclomethasone in the presence of placebo tablets caused worsening of asthma control, demonstrating that patients received clinical benefit from inhaled corticosteroids. Blind removal of beclomethasone in the presence of montelukast resulted in less asthma control but not to the level of the placebo group. All treatments were well tolerated; clinical and laboratory adverse experiences were generally similar to placebo treatment in this study. In conclusion, montelukast provided additional asthma control to patients benefitting from, but incompletely controlled on, inhaled beclomethasone.

Pan-Asian adapted Clinical Practice Guidelines for the management of patients with metastatic non-small-cell lung cancer: a CSCO-ESMO initiative endorsed by JSMO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of metastatic non-small-cell lung cancer (NSCLC) was published in 2016. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and the Chinese Society of Clinical Oncology (CSCO) to convene a special guidelines meeting immediately after the Chinese Thoracic Oncology Group Annual Meeting 2018, in Guangzhou, China. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic NSCLC cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic NSCLC representing the oncological societies of China (CSCO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence, and was independent of both the current treatment practices and the drug availability and reimbursement situations in the six participating Asian countries. During the review process, the updated ESMO 2018 Clinical Practice Guidelines for metastatic NSCLC were released and were also considered, during the final stages of the development of the Pan-Asian adapted Clinical Practice Guidelines.

Immunocytochemical observation of ghrelin-containing neurons in the rat arcuate nucleus

Ghrelin is a novel peptide that stimulates the release of growth hormone from the pituitary and is involved in hypothalamic feeding regulation. A pre-embedding immunostaining technique was used to study the ultrastructure and synaptic relationships of ghrelin-containing neurons in the rat arcuate nucleus (ARC). Ghrelin-like immunoreactive (ghrelin-LI) neurons were found in the ARC, and were especially abundant in its ventral part. At the electron microscopic level, ghrelin-LI neurons received afferent synapses from many unknown axon terminals. Ghrelin-LI products in the immunoreactive cell bodies, processes, and axon terminals were detected mainly in dense granular vesicles about 110 nm in diameter. Ghrelin-LI presynaptic axon terminals often made synapses with unknown immunonegative neurons. These results suggest that ghrelin acts to regulate food intake through synaptic connections in hypothalamic neuronal networks.

The ability of an oligomeric human immunodeficiency virus type 1 (HIV-1) envelope antigen to elicit neutralizing antibodies against primary HIV-1 isolates is improved following partial deletion of the second hypervariable region

Partial deletion of the second hypervariable region from the envelope of the primary-like SF162 virus increases the exposure of certain neutralization epitopes and renders the virus, SF162DeltaV2, highly susceptible to neutralization by clade B and non-clade B human immunodeficiency virus (HIV-positive) sera (L. Stamatatos and C. Cheng-Mayer, J. Virol. 78:7840-7845, 1998). This observation led us to propose that the modified, SF162DeltaV2-derived envelope may elicit higher titers of cross-reactive neutralizing antibodies than the unmodified SF162-derived envelope. To test this hypothesis, we immunized rabbits and rhesus macaques with the gp140 form of these two envelopes. In rabbits, both immunogens elicited similar titers of binding antibodies but the modified immunogen was more effective in eliciting neutralizing antibodies, not only against the SF162DeltaV2 and SF162 viruses but also against several heterologous primary HIV type 1 (HIV-1) isolates. In rhesus macaques both immunogens elicited potent binding antibodies, but again the modified immunogen was more effective in eliciting the generation of neutralizing antibodies against the SF162DeltaV2 and SF162 viruses. Antibodies capable of neutralizing several, but not all, heterologous primary HIV-1 isolates tested were elicited only in macaques immunized with the modified immunogen. The efficiency of neutralization of these heterologous isolates was lower than that recorded against the SF162 isolate. Our results strongly suggest that although soluble oligomeric envelope subunit vaccines may elicit neutralizing antibody responses against heterologous primary HIV-1 isolates, these responses will not be broad and potent unless specific modifications are introduced to increase the exposure of conserved neutralization epitopes.

Simian immunodeficiency virus DNA vaccine trial in macaques

An experimental vaccine consisting of five DNA plasmids expressing different combinations and forms of simian immunodeficiency virus-macaque (SIVmac) proteins has been evaluated for the ability to protect against a highly pathogenic uncloned SIVmac251 challenge. One vaccine plasmid encoded nonreplicating SIVmac239 virus particles. The other four plasmids encoded secreted forms of the envelope glycoproteins of two T-cell-tropic relatives (SIVmac239 and SIVmac251) and one monocyte/macrophage-tropic relative (SIVmac316) of the uncloned challenge virus. Rhesus macaques were inoculated with DNA at 1 and 3, 11 and 13, and 21 and 23 weeks. Four macaques were inoculated intravenously, intramuscularly, and by gene gun inoculations. Three received only gene gun inoculations. Two control monkeys were inoculated with control plasmids by all three routes of inoculation. Neutralizing antibody titers of 1:216 to 1:768 were present in all of the vaccinated monkeys after the second cluster of inoculations. These titers were transient, were not boosted by the third cluster of inoculations, and had fallen to 1:24 to 1:72 by the time of challenge. Cytotoxic T-cell activity for Env was also raised in all of the vaccinated animals. The temporal appearance of cytotoxic T cells was similar to that of antibody. However, while antibody responses fell with time, cytotoxic T-cell responses persisted. The SIVmac251 challenge was administered intravenously at 2 weeks following the last immunization. The DNA immunizations did not prevent infection or protect against CD4+ cell loss. Long-term chronic levels of infection were similar in the vaccinated and control animals, with 1 in 10,000 to 1 in 100,000 peripheral blood cells carrying infectious virus. However, viral loads were reduced to the chronic level over a shorter period of time in the vaccinated groups (6 weeks) than in the control group (12 weeks). Thus, the DNA vaccine raised both neutralizing antibody and cytotoxic T-lymphocyte responses and provided some attenuation of the acute phase of infection, but it did not prevent the loss of CD4+ cells.

A forespore checkpoint for mother cell gene expression during development in B. subtilis

Gene expression in the mother cell compartment of sporulating cells of B. subtilis is partly governed by the mother cell RNA polymerase sigma factor sigma K. Paradoxically, sigma K-directed gene expression also depends on sigma G, the product of the forespore compartment regulatory gene spoIIIG, and on other forespore regulatory proteins. We now identify mutations in the genes bofA and bofB that relieve the dependence of mother cell gene expression on forespore regulatory proteins but not on sigma K. We establish that the dependence of mother cell gene expression on the forespore regulatory proteins is mediated at the level of the conversion of pro-sigma K to its mature, active form. We propose that the bofA and/or bofB proteins govern this conversion in response to a signal generated by the forespore. Activation of pro-sigma K could be a checkpoint for coordinating gene expression between the mother cell and forespore compartments of the developing sporangium.

Arthritis induced in rats with nonimmunogenic adjuvants as models for rheumatoid arthritis

Rat models are useful for studies of the pathogenesis of rheumatoid arthritis (RA) since rats are extraordinarily sensitive to induction of arthritis with adjuvants. Injection of not only the classical complete Freund's adjuvant but also mineral oil without mycobacteria and pure adjuvants such as pristane and squalene, induce severe arthritis in many rat strains. Models like pristane-induced arthritis in rats are optimal models for RA since they fulfill the RA criteria including a chronic relapsing disease course. Arthritogenic adjuvants like pristane, avridine, squalene and mineral oil are not immunogenic since they do not contain major histocompatibility complex (MHC) binding peptides. Nevertheless, the diseases are MHC-associated and dependent on the activation of alphabetaTCR (T-cell receptor)-expressing T cells. However, it has not been possible to link the immune response to joint antigens or other endogenous components although immunization with various cartilage proteins induce arthritis but with different pathogeneses. To unravel the mechanisms behind adjuvant-induced arthritis, a disease-oriented genetic approach is optimal. Several loci that control onset of arthritis, severity and chronicity of the disease have been identified in genetic crosses and most of these have been confirmed in congenic strains. In addition, many of these loci are found in other autoimmune models in the rat as well as associated with arthritis in mice and humans.

The renal medulla and hypertension

We review evidence supporting the conclusion that renal dysfunction underlies the development of all forms of hypertension in humans and experimental animals. Indexes of global renal function are generally normal in the early stages of most genetic forms of hypertension, but renal function is clearly impaired in long-established hypertension. Studies in our laboratory over the past decade summarized below have established that the renal medulla plays an important role in sodium and water homeostasis and in the long-term control of arterial pressure. Development of implanted optical fibers for measurement of cortical and medullary blood flows with laser-Doppler flowmetry and techniques for delivery of vasoactive compounds into the medullary interstitial space enabled us to examine determinants of medullary flow (nitric oxide, atrial natriuretic peptides, kinins, eicosanoids, vasopressin, renal sympathetic nerves, etc). We have shown in spontaneously hypertensive rats that the initial changes of renal function begin as a reduction of medullary blood flow in the absence of changes of cortical flow. Long-term medullary interstitial infusion of captopril, which preferentially increased medullary blood flow, resulted in a lowering of arterial pressure. In normal Sprague-Dawley rats, selective reduction of medullary flow with medullary interstitial or intravenous infusion of small amounts of NG-nitro-L-arginine methyl ester resulted in hypertension. These and other studies we review show that although blood flow to the inner renal medulla comprises less than 1% of the total renal blood flow, changes in flow to this region can have a major effect on sodium and water homeostasis and on the long-term control of arterial blood pressure.

Interleukin 12 at the site of disease in tuberculosis

Interleukin 12 (IL-12), a heterodimeric cytokine composed of p40 and p35 chains, has potent immunologic effects in vitro. We used tuberculous pleuritis as a model to study the immunoregulatory potential of IL-12 in vivo at the site of human infectious disease. Messenger RNAs for p40 and p35 were detected in pleural fluid from six of six patients by reverse-transcription polymerase chain reaction. By using an ELISA that detected both free p40 and heterodimeric IL-12, we found that mean concentrations were 585 +/- 89 pg/ml in pleural fluid of patients with tuberculous pleuritis, which were significantly higher than those in serum of the same patients (54 +/- 36 pg/ml), or in malignant pleural effusions (123 +/- 35 pg/ml). By using an ELISA specific for heterodimeric IL-12, we found that mean concentrations in pleural fluid of patients with tuberculous pleuritis were 165 +/- 28 pg/ml and undetectable in serum of the same patients, or in malignant pleural effusions. Bioactive IL-12 was detectable in five of five supernatants of pleural fluid cells stimulated with Mycobacterium tuberculosis. Addition of anti-IL-12 antibodies suppressed proliferative responses of pleural fluid cells to M. tuberculosis by 36 +/- 7%. These data indicate that IL-12 may play a role in the human immune response to infectious agents in vivo. We hypothesize that IL-12 contributes to the antimycobacterial immune response by enhancing production of interferon-gamma, facilitating development of Th1 cells and augmenting cytotoxicity of antigen-specific T cells and natural killer cells.

Tagged mutations at the Tox1 locus of Cochliobolus heterostrophus by restriction enzyme-mediated integration

We have used the restriction enzyme-mediated integration insertional mutagenesis procedure to tag the Tox1 locus in the filamentous Ascomycete Cochliobolus heterostrophus. Mutations at other, unselected, loci were also identified and a high proportion (30-50%) of them were tagged. This procedure may be of general utility for simultaneously mutating and tagging genes in fungi and in other eukaryotes. The Tox1 locus of C. heterostrophus has been defined by Mendelian analysis as a single genetic element that controls production of T toxin, a linear polyketide involved in virulence of the fungus to its host plant, corn. To tag Tox1, protoplasts of a Tox1+ (T-toxin producing) strain were transformed with a linearized, nonhomologous plasmid along with an excess of the restriction enzyme used to linearize the plasmid. Of 1310 transformants recovered, two produced no detectable T toxin in culture or on corn plants. In each of these transformants, the Tox- mutation mapped at Tox1, was tagged with the selectable marker (hygB) on the transforming plasmid, and was tightly linked to the other tagged Tox- mutation. The two mutations, however, represent two different points of plasmid insertion at the Tox1 locus.

Photopolymerization of multilaminated poly(HEMA) hydrogels for controlled release

A novel approach to immobilize nonuniform initial drug concentration profiles in multilaminated matrix devices utilizing photopolymerization techniques is presented. Solution polymerization of 2-hydroxyethyl methacrylate (HEMA) and diethylene glycol dimethacrylate (DEGDMA) in the presence of a model compound, acid orange 8 (AO8), was conducted using UV light and photoinitiators to construct a laminated matrix device. In this process, each layer was polymerized with a different AO8 concentration to form a nonuniform initial concentration profile in the matrix devices. The AO8 diffusion coefficients measured in this work were used in a concurrently developed model to predict the effects of nonuniform AO8 concentration profiles on AO8 release patterns. The release data predicted by the model agreed well with the experimentally determined data. The results indicate that a zero-order release pattern can be approximated by employing a suitable nonuniform initial drug concentration profile.

Proto-oncogene PML controls genes devoted to MHC class I antigen presentation

Fragments of foreign antigens associated with class I molecules of the major histocompatibility complex (MHC) are presented at the cell surface to elicit an immune response. This presentation requires the coordinated expression of several genes contained in the MHC, including those encoding the MHC class I heavy chain, the proteins LMP-2 and LMP-7, which are involved in the proteasomal degradation of cytosolic antigens into peptide fragments that are destined for association with MHC class I molecules, and TAP-1 and TAP-2, which transport these fragments across the membrane of the endoplasmic reticulum at the start of their journey to the cell surface. In many virus-transformed cell lines and spontaneous tumours, these genes are simultaneously repressed. However, the key factor(s) that are essential for their expression and repression have not been identified. Here we report that the proto-oncogene product PML induces expression of LMP-2, LMP-7, TAP-1 and TAP-2 in an MHC-class I-negative, recurrent tumour, leading to the re-expression of cell-surface MHC in tumours and to rejection of the tumours. PML also regulates MHC expression in untransformed fibroblasts. We conclude that malfunction of PML may enable a tumour to evade the immune defence of its host.

Quantification of non-transferrin-bound iron in the presence of unsaturated transferrin

Non-transferrin-bound iron (NTBI) has been reported to be associated with several clinical states such as thalassemia, hemochromatosis, and in patients receiving chemotherapy. We have investigated a number of ligands as potential alternatives to nitrilotriacetic acid (NTA) to capture NTBI without chelating transferrin- or ferritin-bound iron in plasma. We have established, however, that NTA is the optimal ligand to chelate the different forms of NTBI present in sera and can be adopted for utilization in the NTBI assay. NTA (80 mM) removes all forms of NTBI, while only mobilizing a small fraction of the iron bound to both transferrin and ferritin. We have compared three different detection systems for the quantification of NTA-chelated NTBI: the established HPLC-based method, a simple colorimetric method, and a method based on inductive conductiometric plasma spectroscopy. The sensitivity and reproductibility of the colorimetric method were acceptable compared with the other two methods and would be more convenient as a routine laboratory screening assay for NTBI. However, the limitations of this method are such that it can only be utilized in situations where desferrioxamine is not used and when transferrin saturation levels are close to 100%. Only the HPLC-based method is applicable for patients receiving (desferrioxamine) chelation therapy. In some diseases such as hemochromatosis, transferrin may be incompletely saturated. In such cases, to avoid in vitro donation of iron onto the vacant sites of transferrin, sodium-tris-carbonatocobaltate(III) can be added to block the free iron binding sites on transferrin. If this step is not taken, there may be an underestimation of NTBI values.

X-Linked adrenoleukodystrophy: overview and prognosis as a function of age and brain magnetic resonance imaging abnormality. A study involving 372 patients

The phenotypic expression of X-linked adrenoleukodystrophy (X-ALD) ranges from the rapidly progressive childhood cerebral form to the milder adrenomyeloneuropathy (AMN) in adults. It is not possible to predict phenotype by mutation analysis or biochemical assays. This study reports on 372 patients ranging in age from less than 3 years to adulthood, who have been followed at the Kennedy Krieger Institute. With the aim of determining whether a method could be developed to predict clinical course by analysis of data available at time of first contact, the patients were subdivided into 18 subgroups on the basis of age and the extent of brain magnetic resonance (MRI) abnormality utilizing the MRI scoring system devised by Loes et al. Scores to grade degree of neurologic and neuropsychologic impairment were also developed. There was strong correlation between MRI and the neurology and neuropsychology scores at baseline. Information based exclusively on age and MRI score at time of first contact was highly predictive of future clinical course and should aid the evaluation of the effects of bone marrow transplantation and the selection of patients for this procedure, as well as the evaluation of other therapies that may be developed in the future.

Recombinant Mycobacterium tuberculosis protein associated with mammalian cell entry

The ability to gain entry and resist the antimicrobial intracellular environment of mammalian cells is an essential virulence property of Mycobacterium tuberculosis. A purified recombinant protein expressed by a 1362 bp locus (mce1) in the M. tuberculosis genome promoted uptake into HeLa cells of polystyrene latex microspheres coated with the protein. N-terminus deletion constructs of Mce1 identified a domain located between amino acid positions 106 and 163 that was needed for this cell uptake activity. Mce1 contained hydrophobic stretches at the N-terminus predictive of a signal sequence, and colloidal gold immunoelectron microscopy indicated that the corresponding native protein is expressed on the surface of the M. tuberculosis organism. The complete M. tuberculosis genome sequence revealed that it contained four homologues of mce (mce1, mce2, mce3, mce4) and that they were all located within operons composed of genes arranged similarly at different locations in the chromosome. Recombinant Mce2, which had the highest level of identity (67%) to Mce1, was unable to promote the association of microspheres with HeLa cells. Although the exact function of Mce1 is still unknown, it appears to serve as an effector molecule expressed on the surface of M. tuberculosis that is capable of eliciting plasma membrane perturbations in non-phagocytic mammalian cells.

Use of DNAs expressing HIV-1 Env and noninfectious HIV-1 particles to raise antibody responses in mice

Two DNA constructs encoding portions of the human immunodeficiency virus type-1 (HIV-1) genome have been used to raise antibody responses in BABL/c mice. One DNA (pNL4-3.env) expresses the natural form of the envelope glycoprotein (Env) of HIV-1-NL4-3 (NL4-3). The second (pNL4-3.dpol) produces noninfectious NL4-3 particles. These two DNAs (alone or in combination) raised only transient titers of anti-Env IgG. In the same group in which pNL4-3.dpol DNA raised only transient antibody responses to Env, this DNA raised persistent antibody responses to the p24 virion capsid protein (CA). Antibody responses to Env and CA also showed different abilities to be boosted. The final boosts of pNL4-3.dpol DNA increased titers of anti-CA antibody, but failed to boost the falling titers of anti-Env antibody. At peak titers of anti-Env activity, sera with relatively low ELISA titers of anti-Env IgG (end points of 1:6250) had good titers of neutralizing antibody (approximately 1:3800 for 50 TCID50 of NL4-3). At the end of the experiment (a time when anti-Env antibodies had fallen to near background levels), in vitro-restimulated splenocytes from both pNL4-3.env and pNL4-3.dpol DNA vaccine groups exhibited similar cytotoxic activity.