Phase I and biomarker study of OPB-51602, a novel signal transducer and activator of transcription (STAT) 3 inhibitor, in patients with refractory solid malignancies.

BACKGROUND: The aim of this study was to determine the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of OPB-51602, an oral, direct signal transduction activator of transcription 3 (STAT3) inhibitor, in patients with refractory solid tumors. PATIENTS AND METHODS: Three cohorts were studied: cohort A, a sequential dose escalation of OPB-51602 administered intermittently (days 1-14 every 21 days); cohort B, an expansion cohort evaluating the dose lower than the MTD; cohort C, evaluating continuous daily dosing. RESULTS: Fifty-one patients were studied at 2, 4, and 5 mg per day dosing. The MTD was 5 mg; first-cycle dose-limiting toxicities (DLTs) were grade 3 hyponatremia in one patient, and grade 3 dehydration in another. Intermittent dosing of both 2 and 4 mg doses were tolerable, and the recommended phase II dose was 4 mg. Cohort B investigated 4 mg intermittently, whereas cohort C investigated 4 mg continuously. Common toxicities included fatigue, nausea/vomiting, diarrhea, anorexia, and early-onset peripheral neuropathy. Drug-induced pneumonitis occurred in two patients in cohort C. Continuous dosing was associated with a higher incidence of peripheral neuropathy and a lower mean relative dose intensity, compared with intermittent dosing. Steady-state pharmacokinetics was characterized by high oral clearance, mean elimination half-life ranging from 44 to 61 h, and a large terminal-phase volume of distribution. An active metabolite, OPB-51822, accumulated to a greater extent than OPB-51602. Flow cytometry of peripheral blood mononuclear cells demonstrated pSTAT3 (Tyr(705)) inhibition following exposure. Two patients achieved partial responses at 5 mg intermittently and 4 mg continuously; both had epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor exposure. CONCLUSION: OPB-51602 demonstrates promising antitumor activity, particularly in NSCLC. Its long half-life and poorer tolerability of continuous dosing, compared with intermittent dosing, suggest that less frequent dosing should be explored. CLINICALTRIALSGOV IDENTIFIER: NCT01184807.

The positive impact of cytological specimens for EGFR mutation testing in non-small cell lung cancer: a single South East Asian laboratory's analysis of 670 cases.

OBJECTIVES: To compare the rejection rates of non-small cell lung cancer (NSCLC) samples obtained by differing sampling methods for testing by Sanger sequencing for epidermal growth factor receptor (EGFR) mutations. To assess the association between unsatisfactory outcomes and the quantity of DNA extracted from cytological versus histological samples. METHODS: Six hundred and seventy NSCLC samples referred to our centre from 2008 to 2010 were reviewed as a consequence of sample rejection, presence of EGFR mutations, cytological versus histological sampling methods, DNA quantity and the unsatisfactory genotyping rate. RESULTS: Eighty samples were rejected for testing in similar proportions of histological and cytological samples (11.9% versus 10.9%) usually (n = 75) because the amount of cellular material was judged insufficient in small biopsies or cytology samples. The remaining 590 samples on which EGFR testing was attempted yielded 51 (8.6%) unsatisfactory test outcomes caused by failure of the polymerase chain reaction (PCR) (n = 47 cases), uninterpretable Sanger chromatograms (n = 3 cases) and insufficient DNA extracted for PCR (n = 1 case). The difference in rates of unsatisfactory outcomes between cytological samples (seven of 147 samples or 4.7%) versus tissue samples (44 of 443 samples or 9.9%) was clinically relevant but not statistically significant (Mann-Whitney test; P < 0.081). There was no association between the concentration of DNA extracted and the likelihood of an unsatisfactory analysis; which was similar in all types of sections (large and small) while 0% of 37 cytology slides were unsatisfactory. CONCLUSIONS: Utilizing cytology samples for EGFR testing avoids unnecessary patient re-biopsing and yields a clinically superior satisfactory rate to the overall satisfactory rate of tissue biopsies of NSCLC. The quality rather than quantity of DNA extracted may be a more important determinant of a satisfactory result.

A novel, multilayer structure of a helical peptide.

X-ray diffraction analysis at 1.5 A resolution has confirmed the helical conformation of a de novo designed 18-residue peptide. However, the crystal structure reveals the formation of continuous molecular layers of parallel-packed amphiphilic helices as a result of much more extensive helix-helix interactions than predicted. The crystal packing arrangement, by virtue of distinct antiparallel packing interactions, segregates the polar and apolar surfaces of the helices into discrete and well-defined interfacial regions. An extensive "ridges-into-grooves" interdigitation characterizes the hydrophobic interface, whereas an extensive network of salt bridges and hydrogen bonds dominates the corresponding hydrophilic interface.

Bimolecular triplex formation between 5'-d-(AG)nT4(CT)n and 5'-d-(TC)n as functions of helix length and buffer.

It was observed that a group of unusually stable DNA hairpins (Hn: 5'-d-(AG)nT4(CT)n, n = 2-4) were directed to homopyrimidine sequences (Pn: 5'-d-(TC)n) by py x pu x py-type triplex formation, resulting in high binding affinity and specificity. The spectroscopic results (UV and CD) showed that the short bimolecular triplex Hn:Pn could be formed in acidic conditions (pH 4.5-6.0) as helix length n > 2, and further extending to neutral pH as n = 4. This hairpin strategy for recognition of a pyrimidine strand has a substantial binding advantage over either the conventional linear analog or simple Watson-Crick complement. Triplex stability of Hn with Pn is not only pH-dependent, as expected for triplexes involving C+. GC triads, but also sensitive to the buffer. The triplex H4:P4 was formed in the phosphate buffers of pH 6.0-7.0 but already dissociated above pH 6.5 in the buffer of cacodylate, MOPSO or PIPES. By contrast, the nature of a buffer had no major influence on stability of a hairpin duplex. Here we provide a simple triplex system, and the data presented here may be useful in defining the experimental conditions necessary to stabilize triplex DNA.

Formation of DNA triple helix containing N(4)-(6-aminopyridin-2-yl)-2'-deoxycytidine.

A cytidinyl derivative, N(4)-(6-aminopyridin-2-yl)- 2'-deoxycytidine ((p)C), could interact with a CG base pair to support the triple-helix (triplex) formation of oligodeoxyribonucleotides. Characteristics of (p)C in the formation of both intramolecular triplex, i.e., a "paper clip type" triplex ((P)CT) and intermolecular triplex, i.e., a "linear type" triplex (LT) was monitored by optical methods and isothermal titration calorimetric measurements. Experimental results revealed that the LT with (p)C*CG internally was independent of the solution pH. Only single substitution of (p)C, situated internally but not terminally, facilitated the (P)CT formation by the UV thermal melting study at the neutral pH. However, the best stabilization of the PCT in acidic conditions occurred when (p)C at the end of the triplex rather than internally. In addition, an LT, but not a (P)CT, containing an alternating (p)CT(p)CT(p)C sequence, could be formed in the conditions of 20 mM MgCl(2) and/or 5 mM spermine. Thus, the presence of several nucleotides of (p)C in proximity along the Hoogsteen strand may lead to structural distortion such that the more flexible LT with multiple substitutions is formed in favor of the more rigid PCT.

Probabilistic and sequential computation of optical flow using temporal coherence.

In the computation of dense optical flow fields, spatial coherence constraints are commonly used to regularize otherwise ill-posed problem formulations, providing spatial integration of data. We present a temporal, multiframe extension of the dense optical flow estimation formulation proposed by Horn and Schunck (1981) in which we use a temporal coherence constraint to yield the optimal fusing of data from multiple frames of measurements. Conceptually, standard Kalman filtering algorithms are applicable to the resulting multiframe optical flow estimation problem, providing a solution that is sequential and recursive in time. Experiments are presented to demonstrate that the resulting multiframe estimates are more robust to noise than those provided by the original, single-frame formulation. In addition, we demonstrate cases where the aperture problem of motion vision cannot be resolved satisfactorily without the temporal integration of data enabled by the proposed formulation. Practically, the large matrix dimensions involved in the problem prohibit exact implementation of the optimal Kalman filter. To overcome this limitation, we present a computationally efficient, yet near-optimal approximation of the exact filtering algorithm. This approximation has a precise interpretation as the sequential estimation of a reduced-order spatial model for the optical flow estimation error process at each time step and arises from an estimation-theoretic treatment of the filtering problem. Experiments also demonstrate the efficacy of this near-optimal filter.

A case of penicillamine-induced dermopathy.

INTRODUCTION: We describe an interesting patient with penicillamine-induced dermopathy. CLINICAL PICTURE: A 49-year-old woman presented with a 1-year history of recurrent haemorrhagic blisters, milia and purpura over both her elbows, while on long-term penicillamine therapy (1.5 g daily) for Wilson's disease. Histologically, dermal elastin fibres were markedly reduced in the affected areas, consistent with penicillamine-induced elastolysis. TREATMENT AND OUTCOME: The patient's lesions improved significantly after reduction of her penicillamine dose to 500 mg daily. CONCLUSIONS: The cutaneous side effects of long-term penicillamine therapy are important to recognise as they may be associated with significant morbidity and may be markers of more ominous underlying systemic elastic fibre damage.

Stochastic Petri net modeling of wave sequences in cardiac arrhythmias.

We describe a methodology for modeling heart rhythms observed in electrocardiograms. In particular, we present a procedure to derive simple dynamic models that capture the cardiac mechanisms which control the particular timing sequences of P and R waves characteristic of different arrhythmias. By treating the cardiac electrophysiology at an aggregate level, simple network models of the wave generating system under a variety of diseased conditions can be developed. These network models are then systematically converted to stochastic Petri nets which offer a compact mathematical framework to express the dynamics and statistical variability of the wave generating mechanisms. Models of several arrhythmias are included in order to illustrate the methodology.

Allergic hypersensitivity to lidocaine hydrochloride.

A 39-year-old man developed allergic hypersensitivity to lidocaine hydrochloride and showed urticarial dermographism. Although hypersensitivity reactions to local anesthetics are rare and are usually due to esters of procaine, reaction to the amides of lidocaine can occur. A review of the literature for the past decade revealed only four reported cases of allergic hypersensitivity to lidocaine hydrochloride.

Modeling of cardiac rhythms. A signal-processing perspective.

The authors describe their perspective on the modeling of cardiac rhythms as a component of cardiac arrhythmia signal-processing algorithms. They emphasize that these models are for a specific end purpose and that the aspects of cardiac behavior that are captured by the models are only those relevant for the development of the signal-processing algorithms. The approach is to use statistics to describe ranges of cardiac behavior that share some common feature with respect to the purpose of the signal processing. The statistical approach has the advantage that, coupled with a statistical performance criterion, it specifies an optimal signal-processing algorithm. These optimal algorithms are often computationally intractable, however, especially for real-time use in instruments. Approximations are therefore crucial. The mathematical form of the model is then important since, even if two forms generate identical statistics, the approximations that are natural in different forms can be quite different. Two different mathematical formulations are described--stochastic Petri nets and interacting Markov chains--and the different types of approximately optimal signal-processing algorithms that are natural in these two frameworks are discussed.

The processes of case management: a review of the evaluation of a pilot study for elderly people in Hong Kong.

AIM: This paper is based on research into case management that aimed to evaluate the processes of the introduction of case management for elderly people into the community nursing services in Hong Kong. BACKGROUND: The Hospital Authority in Hong Kong introduced a pilot Case Management scheme into the Community Nursing Services. A research project was therefore developed to evaluate this case management model. METHOD: The processes were measured through information gained from group interviews, daily diaries and weekly activity sheets. FINDINGS: The roles and work practices of the Care Coordinators and Case Managers are described and the benefits of case management to patients, carers and nurses are highlighted. Difficulties are also discussed and good practices are identified. CONCLUSION: Staff in the hospital and community need time to get used to the model of case management and to the accompanying documentation. The role of the case manager needs to be clearly dilineated.

Case management: a review of the definitions and practices.

Case management has been suggested as an innovative strategy which facilitates the linking of quality and cost-effective care. However, there is little consensus about what is actually being introduced under the name of case management. It is suggested that this absence of a clear understanding of case management has been an obstacle in moving forward case management practice and research. This paper presents a critical review of the confusion surrounding case management with an attempt to unravel issues relevant to the implementation of case management into community nursing practice in Hong Kong. It is concluded that there is a need for different definitions of case management as a result of the differences in the cultural and health care context in which it is being practised. Also, if case management programmes are to be advanced, there needs to be more co-ordinated effort in researching not only the expected outcomes but also the structures and processes of these programmes so that findings of similar case management programmes can be compared for ways of future improvement.

Molecular characterization of beta-thalassaemia in Singaporean Chinese: application to prenatal diagnosis.

Sixty-five beta-thalassaemia genes from 14 unrelated Chinese beta-thalassaemia major patients and 37 Chinese beta-carriers were analysed by allele-specific oligonucleotide (ASO) hybridization after DNA amplification by the polymerase chain reaction (PCR). Six mutations were studied and are represented by 49.2% of codon 41-42, 30.8% of IVSII #654, 6.2% of 17 beta, 3.1% of IVSI #5 (G-->C) and 1.5% of -28 TATA box. The complete mutations responsible for beta-thalassaemia major in 13 of our 14 affected families were identified. For these families prenatal diagnosis at 10 weeks gestation using DNA amplification and ASO hybridization will replace the globin chain biosynthesis technique at 19 weeks gestation. Using ASO analysis, our results indicate that 5 oligo-probes (41-42, II-#654, 17 beta, IVSI-#5 and -28) allow determination of beta-thalassaemia mutations in 59/65 (90.8%) of the Singaporean Chinese studied.

The amplification refractory mutation system (ARMS): a rapid and direct prenatal diagnostic technique for beta-thalassaemia in Singapore.

beta-Thalassaemia major patients have chronic anaemia and since 3-4 per cent of Singaporeans carry the beta-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of beta-major. Six mutations along the beta-gene were studied--41-42 (-TCTT), IVSII #654 (C-T), 17 beta (A-T), -28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54.6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the beta-trait carrying the 41-42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the beta-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at -29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our beta-thalassaemia prenatal diagnosis programme in Singapore.

"Paper-clip" type triple helix formation by 5'-d-(TC)3Ta(CT)3Cb(AG)3 (a and b = 0-4) as a function of loop size with and without the pseudoisocytosine base in the Hoogsteen strand.

The formation of a DNA "paper-clip" type triple helix (triplex) with a common sequence 5'-d-(TC)(3)T(a)()(CT)(3)C(b)()(AG)(3) (a and b = 0-4) was studied by UV thermal melting experiments and CD spectra. These DNA oligomers form triplexes and duplexes under slightly acidic and neutral conditions, respectively. The stability of the formed triplexes (at pH 4.5) or duplexes (at pH 7.0 or 8.0) does not vary significantly with the size of the loops (a and b = 1-4). At pH 6.0, the triplex stability is, however, a function of a and b. It is also interesting to note that the oligomer 5'-d-(TC)(3)(CT)(3)(AG)(3) (a and b = 0) forms a stable triplex at pH 4.5 with a slightly lower T(m) value, due to dissociation of a base triad at one end and a distorted base triad at the other, observed by (1)H NMR. Thus, we have here a model system, 5'-d-(TC)(3)T(a)(CT)(3)C(b)(AG)(3), that could form a triplex effectively with (a and b = 1-4) and without (a and b = 0) loops under acidic conditions. In addition, the triplex formation of oligomers with replacement of one, two, or three 2'-deoxycytidine in the Hoogsteen strand by either 2'-deoxypseudoisocytidine (D) or 2'-O-methylpseudoisocytidine (M) was also studied in the sequence 5'-d-(TX)(3)T(2)(CT)(3)C(2)(AG)(3) (where X is C, D, or M). Both CD spectra and UV melting results showed that only D3 [(TX)(3) = (TD)(3)] and M3 [(TX)(3) = (TM)(3)] were able to form the paper-clip structure under both neutral and acidic conditions. This is because the N(3)H of a pseudoisocytosine base can serve as a proton donor without protonation. We hereby proved that the 2'-deoxypseudoisocytidine, similar to 2'-O-methylpseudoisocytidine, could replace 2'-deoxycytidine in the Hoogsteen strand to provide triplex formation at neutral pH.