Defining the molecular pathology of pancreatic body and tail adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) remains a dismal disease, with very little improvement in survival over the past 50 years. Recent large-scale genomic studies have improved understanding of the genomic and transcriptomic landscape of the disease, yet very little is known about molecular heterogeneity according to tumour location in the pancreas; body and tail PDACs especially tend to have a significantly worse prognosis. The aim was to investigate the molecular differences between PDAC of the head and those of the body and tail of the pancreas. METHODS: Detailed correlative analysis of clinicopathological variables, including tumour location, genomic and transcriptomic data, was performed using the Australian Pancreatic Cancer Genome Initiative (APGI) cohort, part of the International Cancer Genome Consortium study. RESULTS: Clinicopathological data were available for 518 patients recruited to the APGI, of whom 421 underwent genomic analyses; 179 of these patients underwent whole-genome and 96 RNA sequencing. Patients with tumours of the body and tail had significantly worse survival than those with pancreatic head tumours (12·1 versus 22·0 months; P = 0·001). Location in the body and tail was associated with the squamous subtype of PDAC. Body and tail PDACs enriched for gene programmes involved in tumour invasion and epithelial-to-mesenchymal transition, as well as features of poor antitumour immune response. Whether this is due to a molecular predisposition from the outset, or reflects a later time point on the tumour molecular clock, requires further investigation using well designed prospective studies in pancreatic cancer. CONCLUSION: PDACs of the body and tail demonstrate aggressive tumour biology that may explain worse clinical outcomes.

ADAM12 is a circulating marker for stromal activation in pancreatic cancer and predicts response to chemotherapy.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by abundant stroma that harbors tumor-promoting properties. No good biomarkers exist to monitor the effect of stromal targeting therapies or to predict response. We set out to identify such non-invasive markers for PDAC stroma and predict response to therapy. Gene expression datasets, co-culture experiments, xenografts, and patient samples were analyzed. Serum samples were measured from a cohort of 58 resected patients, and 87 metastatic or locally advanced PDAC patients. Baseline and follow-up levels were assessed in 372 additional metastatic PDAC patients who received nab-paclitaxel with gemcitabine (n = 184) or gemcitabine monotherapy (n = 188) in the phase III MPACT trial. Increased levels of ADAM12 were found in PDAC patients compared to healthy controls (p < 0.0001, n = 157 and n = 38). High levels of ADAM12 significantly associated with poor outcome in resected PDAC (HR 2.07, p = 0.04). In the MPACT trial survival was significantly longer for patients who received nab-paclitaxel and had undetectable ADAM12 levels before treatment (OS 12.3 m vs 7.9 m p = 0.0046). Consistently undetectable or decreased ADAM12 levels during treatment significantly associated with longer survival as well (OS 14.4 m and 11.2 m, respectively vs 8.3, p = 0.0054). We conclude that ADAM12 is a blood-borne proxy for stromal activation, the levels of which have prognostic significance and correlate with treatment benefit.

The effects of cyanide and iodoacetate intoxication and ischaemia on enzyme release from the perfused rat heart.

Isolated rat hearts perfused in the presence of iodoacetate show inhibition of glycolysis and release enzymes into the perfusate. Hearts perfused with cyanide, a mitochondrial inhibitor, show acceleration of glycolysis and no enzyme release. The adenine nucleotide content of the iodoacetate, but not the cyanide-perfused hearts was reduced. These results indicate that the membranes were permeable in the former treatment group. The adenylate energy charge and the ATP content of both the cyanide and iodoacetate treatment groups were similar but, as the extent of enzyme release was quite different, it appears that the energy state of the cell was not the prime factor controlling membrane integrity. Isolated perfused hearts were rendered ischaemic by placing a one-way ball valve in the aortic outflow tract. ATP concentration declined, as did ADP after an initial rise of short duration. AMP concentrations rose as the time of ischaemia increased. At the time at which enzyme release was first determined, the intracellular total adenine nucleotide content began to decline, suggesting that the membrane had become permeable to both small and large molecules. Glycolysis was stimulated by the hypoxia induced in the preparation and then this increase became inhibited. The point at which this inhibition was observed was also the point at which membrane permeability was evident. Taken together, the data from these experiments suggest that the energy derived from the activity of the glycolytic pathway may be important to the heart for maintenance of membrane function, particularly in ischaemia.

Lowered rates of protein synthesis by mitochondria isolated from organisms of increasing age.

The rate of protein synthesis was measured in isolated mitochondria from Drosophila melanogaster and from the livers and kidneys of C57BL/6J mice of increasing ages. Over the life-span of the organisms, the synthesis of mitochondrial proteins decreased to a level which was less than half the original rate. Concomitant with this decrease, the amount of mitochondria which could be isolated from the organisms declined by about 30%. Thus, the separate translational system of mitochondria exhibited an age-related decrease in activity which was in addition to the decrease already observed in the cytoplasmic ribosomal system.

Repression of basal transcription by vitamin D receptor: evidence for interaction of unliganded vitamin D receptor with two receptor interaction domains in RIP13delta1.

Repression of basal transcription of a 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) responsive 25-hydroxyvitamin D3-24-hydroxylase (CYP24) promoter construct as observed in kidney cells in the absence of ligand and this repression was dependent on a functional vitamin D response element (VDRE). Basal repression was also seen with a construct where a consensus DR-3-type VDRE was fused to the thymidine kinase promoter. Expression of a dominant negative vitamin D receptor (VDR) isoform that strongly bound to the VDRE motif in the CYP24 promoter ablated basal repression. This VDR isoform lacked sequence in the hinge- and ligand-binding domains implicating one or both of these domains in basal repression. It is well known that thyroid hormone and retinoic acid receptors silence basal transcription of target genes in the absence of ligands and this repressor function can be mediated by the nuclear receptor corepressor N-CoR. Two variants of N-CoR have been described, RIP13a and RIP13delta1. N-CoR and the variants contain two receptor interaction domains, ID-I and ID-II, which are identical except region ID-II in RIP13delta1 has an internal deletion. We have used the mammalian two hybrid system to investigate whether VDR, in the absence of ligand 1,25-(OH)2D3, can interact with these domains. The data showed that unliganded VDR does not interact with either ID-I or ID-II from RIP13a and RIP13delta1, but does interact strongly with a composite domain of ID-I and ID-II from RIP13delta1 (but not from RIP13a) and this strong interaction is abrogated in the presence of ligand. This finding implicates RIP13delta1 in VDR-dependent basal repression of the promoter constructs under investigation. However, over-expression of RIP13delta1 in kidney cell lines did not alter basal expression of the CYP24 promoter construct. It is concluded that either the level of endogenous RIP13delta1 in these kidney cells permits maximal repression or that repression occurs by a mechanism that is independent of RIP13delta1. Alternatively, repression may be dependent on RIP13delta1 but requires an additional cofactor that is limiting in these cells.

Synthesis and antiinflammatory/analgesic activities of 11H-dibenzo[b, e,][1,4]dioxepinacetic acids.

A new class of tricyclic arylacetic acids was synthesized and evaluated as antiinflammatory/analgesic agents as well as inhibitors of prostaglandin synthetase. 11H-Dibenzo[b,e][1,4]dioxepin-2-, -3, -7, and -8-acetic and alpha-methylacetic acids and their derivatives were prepared by cyclization of diaryl ether precursors or by condensation of catechol and an aryl dihalide. The most potent compound in the carrageenan foot edema assay was alpha-methyl-11H-dibenzo[b,e][1,4]dioxepin-8-acetic acid (1 mg/kg = 43% inhibition). The most potent enzyme inhibitors were the 2-acetic acid and the alpha-methyl-7-acetic acid (IC50 = 0.1 microM). Some of these compounds were also found to be highly ulcerogenic.

Lysosomotropic agents. 4. Carbobenzoxyglycylphenylalanyl, a new protease-sensitive masking group for introduction into cells.

Bioactive primary and secondary amines, when acylated with the Z-Gly-Phe group, are transported into pinocytic cells, such as macrophages, P-815 mastocytoma, SV-40 3T3, and leukemia 1210, much faster than the parent compounds. Amines such as lysosomotropic detergents [R. A. Firestone, J. M. Pisano, and R. J. Bonney, J. Med. Chem., 22, 1130 (1979) and nitrogen mustard, which are deactivated by acylation, are unmasked by enzymic action intracellularly, probably in lysosomes because an acidic pH maximum in activity exists which acts only on the L isomer. The added polarity and molecular weight brought about by acylation prevents the amines' normally facile entry into cells by simple diffusion, restricting it to an active-transport mechanism.

Immune complexes and inflammation. A study of the activity of anti-inflammatory drugs in the reverse passive arthus reaction in the rat.

The reverse passive Arthus reaction in rat skin was quantitated by using increase in wet weight as a measure of edema and extractable myeloperoxidase as a measure of the intensity of polymorphonuclear leukocyte (PMN) infiltration. Treatment of the animal with dexamethasone prior to challenge with antigen/antibody resulted in an inhibition of both edema and the infiltration of inflammatory cells. In contrast, the non-steroidal anti-inflammatory drugs inhibited the intensity of cell infiltration (PMNs but not mononuclear cells) without affecting edema. The results are discussed in the light of the effects of these drugs on arachidonic acid oxidation.

A biochemical study of the cotton pellet granuloma in the rat. Effects of dexamethasone and indomethacin.

The subcutaneous implantation of a cotton pellet into a rat results in the formation of a granuloma at the site of the implant. The early events comprise an accumulation of fluid and protein-aceous material together with an infiltration of neutrophils. The granuloma formed by day 7 is characterized by the formation of a vascularized fibrous capsule containing fibroblasts and infiltrating mononuclear cells which are rich in N-acetyl-beta-D-glucosaminidase (NAG). Granuloma development was quantitated by dry weight measurements, and its cellular content was measured by assaying activity of NAG and total nucleic acid content. Nucleic acid determinations showed that cell infiltration into the granuloma took place at a virtually constant rate over a 7-day period. In contrast, the NAG activity did not change significantly until after day 5 when a large increase in the amount of enzyme extractable from the granuloma was seen. Systemic treatment of the animal with dexamethasone or indomethacin resulted in an inhibition of granuloma weight gain, NAG activity and nucleic acid levels. The data suggest that the two drugs acted during the early phase of granuloma development at the level of cell infiltration. Both drugs given on days 0-3 alone suppressed granuloma formation, whereas treatment on days 4-7 was without effect.

Transcriptional repression by COUP-TF II is dependent on the C-terminal domain and involves the N-CoR variant, RIP13delta1.

COUP-TF II/ARP-1 is an 'orphan' steroid receptor that inhibits basal transcription, and represses trans-activation by the vitamin D, thyroid hormone and retinoid receptors. The molecular basis of repression by COUP-TF II remains obscure. In this study we utilized the GAL4 hybrid system to demonstrate that COUP-TF II contains sequences within the C-terminal region that encode a dominant transcriptional repressor that inhibits the ability of the potent chimeric transactivator GAL4VP16 to induce transcription. Mammalian two hybrid analysis demonstrated that COUP-TF II did not efficiently interact with either interaction domains I or II from N-CoR and RIP13. However, COUP-TF II efficiently interacts with a region comprised of interaction domains I + II from the corepressor, RIP13delta1. Efficient interaction of the orphan receptor with the corepressor was critically dependent on a large region comprised of the C, D and E domains of COUP-TF II, which correlated with the domain that maximally represses transcription. This investigation suggested that the N-CoR variant, RIP13delta1 interacts with a region of COUP-TF II that functions as a dominant transcriptional repressor.

Information in speech: observations on the perception of [s]-stop clusters.

A series of experiments is reported that investigated the pattern of acoustic information specifying place and manner of stop consonants in medial position after [s]. In both production and perception, information for stop place includes the spectrum of the fricative at offset, the duration of the silent closure interval, the spectral relationship between the frequency of the stop release burst and the following periodically excited formants, and the spectral and temporal characteristics of the first formant transition. Similarly, the information for stop manner includes the duration of silent closure, the frequency of the first formant at the release, the magnitude of the first formant transition, and the proximity of the second and third formants at release. A relationship was shown to exist in perception between the spectral characteristics of the first formant and the duration of the silent closure required to hear a stop. This appears to reciprocate the covariation of these parameters in production across different places of articulation and different vocalic contexts. The existence of perceptual sensitivity to a wide range of the acoustic consequences of production questions the efficacy of accounts of speech perception in terms of the fractionation of the signal into elemental acoustic cues, which are then integrated to yield a phonetic percept. It is argued that it is inappropriate to ascribe a psychological status to cues whose only reality is their operational role as physical parameters whose manipulation can change the phenotic interpretation of a signal. It is suggested that the metric of the information for phonetic perception cannot be that of the cues; rather, a metric should be sought in which acoustic and articulatory dynamics are isomorphic.

Spectral regularity as a factor distinct from harmonic relations in auditory grouping.

When the regular spectral pattern formed by an odd-harmonic complex (the base) is disrupted by an added even harmonic, the added component is judged as more salient than its neighbors. This study considered whether the effects of spectral pattern on perceptual segregation are restricted to harmonic stimuli. Participants either rated the clarity or judged the relative pitch of a cued component in a series of complex tones. The difference in clarity between added and base components found for the harmonic complexes was not reduced when the complexes were made inharmonic either by a frequency shift or by spectral stretch or compression. However, the added-base difference could be abolished for an inharmonic complex when the distribution of components across frequency was made uniform. These findings suggest that spectral regularity is a factor distinct from harmonic relations in auditory grouping.

Auditory spatial attention using interaural time differences.

Previous probe-signal studies of auditory spatial attention have shown faster responses to sounds at an expected versus an unexpected location, making no distinction between the use of interaural time difference (ITD) cues and interaural-level difference cues. In 5 experiments, performance on a same-different spatial discrimination task was used in place of the reaction time metric, and sounds, presented over headphones, were lateralized only by an ITD. In all experiments, performance was better for signals lateralized on the expected side of the head, supporting the conclusion that ITDs can be used as a basis for covert orienting. The performance advantage generalized to all sounds within the spatial focus and was not dissipated by a trial-by-trial rove in frequency or by a rove in spectral profile. Successful use by the listeners of a cross-modal, centrally positioned visual cue provided evidence for top-down attentional control.

A comparison of the effects of quetiapine ('seroquel') and haloperidol in schizophrenic patients with a history of and a demonstrated, partial response to conventional antipsychotic treatment. PRIZE Study Group.

Quetiapine ('Seroquel') is a well-tolerated, novel, atypical antipsychotic with consistent efficacy in the treatment of schizophrenia. To date, no clinical studies have evaluated the effect of quetiapine in patients who only partially respond to conventional antipsychotics, yet this type of patient is most frequently seen by psychiatrists. Therefore, this international, multicentre, double-blind study was conducted to compare the efficacy and tolerability of 8 weeks' treatment of quetiapine 600 mg/day with haloperidol 20 mg/day in 288 patients who had a history of partial response to conventional antipsychotics and displayed a partial or no response to 1 month of fluphenazine (20 mg/day) treatment. Patients on quetiapine tended to have greater improvement than those on haloperidol in the primary efficacy measure, mean Positive and Negative Symptom Scale (PANSS) score, after 4 weeks' treatment (-9.05, -5.82, respectively, P = 0.061) and at study end (-11.50, -8.87, respectively, P = 0.234). Similarly, there was a trend towards patients on quetiapine demonstrating greater improvements in the secondary efficacy measures (Clinical Global Impression, PANSS subscale and Brief Psychiatric Rating Scale scores) [week 4 (baseline) to week 12 (end)], but the difference between treatments did not reach significance. Significantly more patients on quetiapine than on haloperidol showed a clinical response-patient response rates, defined as > 20% reduction in PANSS total score between weeks 4 and 12, were 52.2% for quetiapine and 38.0% for haloperidol (P = 0.043). Patients receiving quetiapine required less anticholinergic medication (P < 0.011), had greater reduction in extrapyramidal symptoms (EPS) (P = 0.005) and fewer treatment-emergent EPS-related adverse events compared to those on haloperidol (P < 0.001). Serum prolactin concentrations were elevated at the end of fluphenazine treatment in 73% of patients. Between weeks 4 and 12, elevated serum prolactin concentrations significantly decreased in quetiapine-treated patients compared to those receiving haloperidol (P < 0.001). At the end of quetiapine treatment, 83% of patients had normal prolactin levels while only 21% of patients receiving haloperidol were within the normal range. These results suggest that quetiapine may make a valuable contribution to the management of patients with a history of partial response to conventional antipsychotics.

Cultured neonate rat myocytes as a model for the study of myocardial ischaemic necrosis.

The preparation of cultures of neonate rat heart muscle cells is described. These cultures, when subjected to anoxia, show enzyme release that can be directly related to the uptake of a vital dye such trypan blue. Enzyme release is a valid method of estimating cell necrosis in this model. The survival of anoxic cultures is closely associated with glycolytic activity. Glycolysis rate falls and enzyme release increases as the medium glucose concentration is reduced. If glycolysis is inhibited by either 2-deoxyglucose or L-lactate, enzyme release under anoxic conditions is enhanced. Enzyme release correlates inversely with glycolytic activity and the intracellular ATP content of the cultures. Addition of ATP to anoxic cultures partially ameliorates the effect of the anoxia on enzyme release. Elevation of the calcium content of the culture medium exacerbates the damage caused to cardiac myocytes by anoxic insult. This effect can be obtunded by calcium-antagonist drugs such as verapamil or nifedipine and can be explained in terms of reduction in utilization of intracellular ATP by the anoxic monocytes. These observations indicate that cultured myocytes may represent a useful model of hypoxic injury against which novel pharmacological agents, that may reduce hypoxic or ischaemic injury in vivo, could be evaluated.

Rapid auditory processing and phonological ability in normal readers and readers with dyslexia.

According to a prominent theory, the phonological difficulties in dyslexia are caused by an underlying general impairment in the ability to process sequences of rapidly presented, brief sounds. Two studies examined this theory by exploring the relationships between rapid auditory processing and phonological processing in a sample of 82 normally reading children (Study 1) and by comparing 17 children with dyslexia to chronological-age and reading-age control participants on these tasks (Study 2). In the normal readers, moderate correlations were found between the measure of rapid auditory processing (Auditory Repetition Task, or ART) and phonological ability. On the ART, the dyslexia group performed at a level similar to that of the reading-age control group but obtained scores that were significantly below those of the chronological-age control group. This difference was due to a subgroup of 4 children in the dyslexia group who had particular difficulty with the ART. The phonological skills of these individuals were not worse than those of the children in the dyslexia group who were unimpaired on the ART. The discussion argues that there is no evidence that phonoogical difficulties are secondary to impairments of rapid auditory processing, as measured by the ART, and highlights the need to examine the strategic and cognitive demands involved in tasks of rapid auditory processing.