POS1048 SAFETY AND EFFICACY OF DEUCRAVACITINIB, AN ORAL, SELECTIVE TYROSINE KINASE 2 INHIBITOR, IN PATIENTS WITH PSORIATIC ARTHRITIS: 52-WEEK RESULTS FROM A RANDOMISED PHASE 2 TRIAL

Background

Deucravacitinib (DEUC) is a novel, oral, selective, allosteric inhibitor of tyrosine kinase 2 (TYK2) that acts by binding to the unique TYK2 regulatory domain, thereby suppressing signalling of key cytokines (eg, IL-23) involved in skin psoriasis and psoriatic arthritis (PsA) pathogenesis. Results from the initial 16-week (wk), placebo (PBO)-controlled period (Part A) of a 52-wk, blinded Phase 2 trial in PsA showed that DEUC was significantly more efficacious than PBO.1 The Psoriatic Arthritis Disease Activity Score (PASDAS), a validated comprehensive measure assessing a variety of PsA clinical domains, was used to assess efficacy of DEUC up to 52 wks.

Objectives

Evaluate the safety and efficacy of DEUC in Part B (Wks 16-52) in the Phase 2 PsA trial.

Methods

Patients (pts) with PsA were randomised 1:1:1 to PBO, DEUC 6 mg once daily (QD), or 12 mg QD. After Wk 16 (Part A), pts could enrol in an optional, double-blind period until Wk 52 (Part B). In Part B, pts receiving DEUC who had achieved minimal disease activity (MDA) at Wk 16 continued DEUC treatment and those who had not achieved MDA were switched to ustekinumab (UST) at the approved PsA dose. All pts treated with PBO in Part A switched to UST in Part B. Pts were assessed up to 52 wks for adverse events (AEs) and exploratory efficacy endpoints including change in PASDAS. Analyses were descriptive using data as observed.

Results

Of 203 pts randomised in Part A, 180 (89%) completed 16 wks of treatment and 173 (96%) of these pts chose to enrol in Part B. Of 118 pts initially randomised to DEUC, 25% (29/118; 6 mg QD, 22% [13/60]; 12 mg QD, 28% [16/58]) achieved MDA at Wk 16 and continued at the same dose. All other pts switched to UST in Part B: PBO, 100% (55/55; including 5 pts who had achieved MDA at Wk 16); DEUC 6 mg QD, 78% (47/60); DEUC 12 mg QD, 72% (42/58). The safety profile of DEUC in Part B (Table 1) was consistent with that in Part A, and all AEs were mild or moderate except 2 AEs in 1 pt with severe cataract/macular fibrosis. There were no opportunistic infections, herpes zoster, malignancy, thrombotic events, or treatment-related serious AEs reported in pts who remained on DEUC. Decreases in mean PASDAS score observed at Wk 16 were maintained at Wk 52 in pts who continued on DEUC (Figure 1). Improvements in other outcomes, including ACR components, PASI, and FACIT-Fatigue, were also sustained at Wk 52 in pts who continued DEUC treatment. Pts who had not achieved MDA on DEUC at Wk 16 showed a decrease in mean PASDAS score at Wk 52 after switching to UST.

Table 1.

Overall summary of safety in Part B (Weeks 16 to 52)

AE, n (%)aDEUC 6 mg QD n = 13DEUC 12 mg QD n = 16DEUC 6 mg QD →UST n = 47DEUC 12 mg QD → UST n = 42PBO → UST n = 55Total AEs11 (84.6)8 (50.0)26 (55.3)26 (61.9)30 (54.5)Deaths001 (2.1)d1 (2.4)d0SAE1 (7.7)b03 (6.4)4 (9.5)0Treatment-related SAE00000Discontinued due to AE01 (6.3)c02 (4.8)c,e0

Includes all treated patients in Part B. Medical Dictionary for Regulatory Activities version 23.0 was used. an is the number of patients who experienced an event. bOne patient had SAEs of psoriatic arthropathy in 1 joint and peripheral neuropathy. cPatient had an AE of COVID-19 infection leading to discontinuation. dDeaths in UST arms were due to car accident and sudden death in a 71-year-old patient with hypertension. ePatient had an AE of urinary tract infection leading to discontinuation.

AE, adverse event; DEUC, deucravacitinib; PBO, placebo; QD, once daily; SAE, serious adverse event; UST, ustekinumab.

Conclusion

In the 16- to 52-wk blinded Part B of a Phase 2 study in pts with PsA, no new safety signals were observed with continuous DEUC treatment vs the earlier Part A period. Efficacy in PASDAS, as well as other key efficacy measures, was maintained with continued DEUC treatment through Wk 52.

References

[1]Mease PJ et al. Efficacy and Safety of Selective TYK2 Inhibitor, Deucravacitinib, in a Phase 2 Trial in Psoriatic Arthritis. Ann Rheum Dis. (In Press).

Acknowledgements

This study was sponsored by Bristol Myers Squibb. Professional medical writing assistance was provided by Julianne Hatfield, PhD at Peloton Advantage, LLC, an OPEN Health company, Parsippany, NJ, USA, and funded by Bristol Myers Squibb. The authors acknowledge Jonghyeon Kim, PhD, who was employed by Bristol Myers Squibb at the time the study was conducted, for his statistical assistance.

Disclosure of Interests

Philip J Mease Consultant of: Consulting and/or speaker fees: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Janssen, Novartis, Pfizer, SUN Pharma, and UCB., Grant/research support from: Research grants: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Janssen, Novartis, Pfizer, SUN Pharma, and UCB;, Atul Deodhar Consultant of: Consulting and/or advisory boards: AbbVie, Amgen, Aurinia, Bristol Myers Squibb, Celgene, Eli Lilly, GlaxoSmithKline, Janssen, MoonLake, Novartis, Pfizer, UCB, Grant/research support from: Research grants: AbbVie, Eli Lilly, GlaxoSmithKline, Novartis, Pfizer, and UCB., Désirée van der Heijde Consultant of: Consulting fees: AbbVie, Bayer, Bristol Myers Squibb, Cyxone, Eisai, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Janssen, Novartis, Pfizer, and UCB Pharma; Director: Imaging Rheumatology BV., Frank Behrens Consultant of: Consultancies/speaker fees: AbbVie, Amgen, Boehringer, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly, Boehringer, Sandoz, and Sanofi., Grant/research support from: Research Support: AbbVie, Pfizer, Roche, Chugai, Prophylix, Novartis, and Amgen, Alan Kivitz Shareholder of: Shareholder: Pfizer, Sanofi, GlaxoSmithKline, Gilead Sciences, Inc., Novartis, Consultant of: Paid Consultant: AbbVie, Boehringer Ingelheim, Flexion, Janssen, Pfizer, Sanofi, Regeneron, SUN Pharma Advanced Research, Gilead Sciences, Inc., Speakers bureau: Celgene, Merck, Lilly, Novartis, Pfizer, Sanofi, Genzyme, Flexion, AbbVie., Jeffrey Neal Grant/research support from: Research grants to foundation: AbbVie, Amgen, Eli Lilly, Genentech, Novartis, UCB, Pfizer, Gilead, and Bristol Myers Squibb., Marleen Nys Shareholder of: Bristol Myers Squibb., Employee of: Bristol Myers Squibb., Thomas Lehman Shareholder of: Bristol Myers Squibb., Employee of: Bristol Myers Squibb., Nikolay Delev Shareholder of: Bristol Myers Squibb., Employee of: Bristol Myers Squibb., Shimon Korish Shareholder of: Bristol Myers Squibb., Employee of: Bristol Myers Squibb., Miroslawa Nowak Shareholder of: Bristol Myers Squibb., Employee of: Bristol Myers Squibb., Subhashis Banerjee Shareholder of: Bristol Myers Squibb., Employee of: Bristol Myers Squibb.

Immune checkpoint inhibitors for patients with advanced lung cancer and oncogenic driver alterations: results from the IMMUNOTARGET registry

Background

Anti-PD1/PD-L1 directed immune checkpoint inhibitors (ICI) are widely used to treat patients with advanced non-small-cell lung cancer (NSCLC). The activity of ICI across NSCLC harboring oncogenic alterations is poorly characterized. The aim of our study was to address the efficacy of ICI in the context of oncogenic addiction.

Patients and methods

We conducted a retrospective study for patients receiving ICI monotherapy for advanced NSCLC with at least one oncogenic driver alteration. Anonymized data were evaluated for clinicopathologic characteristics and outcomes for ICI therapy: best response (RECIST 1.1), progression-free survival (PFS), and overall survival (OS) from ICI initiation. The primary end point was PFS under ICI. Secondary end points were best response (RECIST 1.1) and OS from ICI initiation.

Results

We studied 551 patients treated in 24 centers from 10 countries. The molecular alterations involved KRAS (n = 271), EGFR (n = 125), BRAF (n = 43), MET (n = 36), HER2 (n = 29), ALK (n = 23), RET (n = 16), ROS1 (n = 7), and multiple drivers (n = 1). Median age was 60 years, gender ratio was 1 : 1, never/former/current smokers were 28%/51%/21%, respectively, and the majority of tumors were adenocarcinoma. The objective response rate by driver alteration was: KRAS = 26%, BRAF = 24%, ROS1 = 17%, MET = 16%, EGFR = 12%, HER2 = 7%, RET = 6%, and ALK = 0%. In the entire cohort, median PFS was 2.8 months, OS 13.3 months, and the best response rate 19%. In a subgroup analysis, median PFS (in months) was 2.1 for EGFR, 3.2 for KRAS, 2.5 for ALK, 3.1 for BRAF, 2.5 for HER2, 2.1 for RET, and 3.4 for MET. In certain subgroups, PFS was positively associated with PD-L1 expression (KRAS, EGFR) and with smoking status (BRAF, HER2).

Conclusions

: ICI induced regression in some tumors with actionable driver alterations, but clinical activity was lower compared with the KRAS group and the lack of response in the ALK group was notable. Patients with actionable tumor alterations should receive targeted therapies and chemotherapy before considering immunotherapy as a single agent.

Renal Outcomes of Liver Transplantation Recipients Receiving Standard Immunosuppression and Early Renal Sparing Immunosuppression: A Retrospective Single Center Study

New-onset stage 4-5 chronic kidney disease (CKD) after liver transplantation (LT) is associated with high morbidity, mortality, and economic burden. In 2010, we instituted an early renal sparing immunosuppression (RSI) protocol for LT recipients with severe renal dysfunction (pre-LT dialysis/estimated glomerular filtration rate (eGFR)<30mL/min/1.73 m2 or post-LT acute kidney injury) consisting of 2 doses of basiliximab for induction and delaying tacrolimus to post-LT day 4-7. We examined the effect of early RSI on post-LT renal outcomes.

METHODS

Data on all adults who had LT between January 1, 2010, and December 12, 2014 were collected. We calculated the renal risk index (RRI) score for each LT recipient (https://rri.med.umich.edu). Primary outcome was new-onset post-LT stage 4-5 CKD.

RESULTS

Of 214 LT recipients, 121 (57%) received early RSI and 93 (43%) received standard immunosuppression. Cumulative incidence of new-onset stage 4-5 CKD was higher in early RSI compared with standard immunosuppression (P = 0.03). Female sex and RRI score were the significant risk factors for development of post-LT stage CKD in the entire study cohort as well as the LT recipients with RRI ≥ sixth decile (high-risk group).

CONCLUSIONS

Delaying tacrolimus initiation combined with basiliximab induction did not have a durable effect on long-term renal outcomes in high-risk LT recipients. Further studies are needed to identify the effective strategies to preserve renal function by targeting patients at high risk for CKD progression.

Adenosine A2A and A2B receptor expression in neuroendocrine tumours: potential targets for therapy

The clinical management of neuroendocrine tumours is complex. Such tumours are highly vascular suggesting tumour-related angiogenesis. Adenosine, released during cellular stress, damage and hypoxia, is a major regulator of angiogenesis. Herein, we describe the expression and function of adenosine receptors (A(1), A(2A), A(2B) and A(3)) in neuroendocrine tumours. Expression of adenosine receptors was investigated in archival human neuroendocrine tumour sections and in two human tumour cell lines, BON-1 (pancreatic) and KRJ-I (intestinal). Their function, with respect to growth and chromogranin A secretion was carried out in vitro. Immunocytochemical data showed that A(2A) and A(2B) receptors were strongly expressed in 15/15 and 13/18 archival tumour sections. Staining for A(1) (4/18) and A(3) (6/18) receptors was either very weak or absent. In vitro data showed that adenosine stimulated a three- to fourfold increase in cAMP levels in BON-1 and KRJ-1 cells. The non-selective adenosine receptor agonist (adenosine-5'N-ethylcarboxamide, NECA) and the A(2A)R agonist (CGS21680) stimulated cell proliferation by up to 20-40% which was attenuated by A(2B) (PSB603 and MRS1754) and A(2A) (SCH442416) receptor selective antagonists but not by the A(1) receptor antagonist (PSB36). Adenosine and NECA stimulated a twofold increase in chromogranin A secretion in BON-1 cells. Our data suggest that neuroendocrine tumours predominantly express A(2A) and A(2B) adenosine receptors; their activation leads to increased proliferation and secretion of chromogranin A. Targeting adenosine signal pathways, specifically inhibition of A(2) receptors, may thus be a useful addition to the therapeutic management of neuroendocrine tumours.

Optimal choice of dairy forages in eastern Australia

Although several forage species such as perennial ryegrass are predominant, there is a wide range of forage species that could be grown in subtropical and temperate regions in Australia as dairy pastures. These species have differing seasonal patterns of growth, nutrient quality, and water-use efficiency, as demonstrated in a large experiment evaluating over 30 species at the University of Sydney (Camden, New South Wales, Australia). Some species can be grazed, whereas others require mechanical harvesting, which incurs a further cost. Previous comparisons of species that relied on yield of dry matter per unit of some input (typically land or water) did not simultaneously take into account the season in which forage is produced, or other factors related to the costs of production and delivery to the cows. To effectively compare the profitability of individual species, or combinations of species, requires the use of a whole-farm, multiperiod model. Linear programming was used to find the most profitable mix of forage species for an irrigated dairy farm in a warm temperate irrigation region of New South Wales, Australia. It was concluded that for a typical farmer facing the prevailing milk and purchased feed prices with average milk production per cow, the most profitable mix of species would include a large proportion of perennial ryegrass (Lolium perenne) and prairie grass (Bromus willdenowii). The result was robust to changes in seasonal milk pricing and a move from year-round to a more seasonal calving pattern.

Environment. Sustainable development of the agricultural bio-economy

A U.S. farm policy shift to joint production of commodities and ecological services will advance sustainable agriculture.

Digital pulse shape discrimination

Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogoue techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogoue signal processing. Results illustrate the effectiveness of digital PSD.

Transsphenoidal surgery for acromegaly in wales: results based on stringent criteria of remission

We retrospectively analyzed 90 patients who underwent transsphenoidal surgery (performed by three surgeons) in our center as initial therapy for acromegaly. We used a combination of modern, evidence-based remission criteria including mean day curve GH less than 2.5 micro g/liter (5 mU/liter), a nadir GH less than 1.0 micro g/liter (2 mU/liter) after an oral glucose tolerance test, and normal age-related IGF-I levels (where available). Fifty-seven of 90 (63%) patients remained in remission after surgery. Seventy-nine percent of patients with microadenomas but only 56% of patients with macroadenomas achieved remission (P < 0.001). Eighty-six percent of patients with preoperative GH levels below 10 micro g/liter (day profile or after oral glucose tolerance test) went into remission, compared with 51% of patients with GH levels above 25 micro g/liter at diagnosis (P < 0.002). The remission rate was also related to the period of surgery that was significantly higher in 1998-2001 (76%; P < 0.05) compared with 1990-1997 (54%) and 1980-1989 (63%). There were no recurrences or perioperative deaths. Meningitis occurred in 3% of patients, cerebrospinal fluid rhinorrhea in 7%, and permanent diabetes insipidus in 15%. The proportion of patients who developed new anterior pituitary hormone deficiencies and panhypopituitarism was significantly less in the period 1998-2001 (P < 0.001) when compared with the periods from 1990-1997 and 1980-1989. Transsphenoidal surgery is a safe and effective treatment for acromegaly, and our results compare favorably with those from published series. The presence of an intrasellar lesion and low preoperative GH levels is a good predictor of remission in the long term, but historically in our center this can only be achieved in a significant proportion of patients at the expense of some degree of hypopituitarism. However, surgical outcome in our center, including a reduced frequency of hypopituitarism, has improved significantly over time, coincident with the arrival of a dedicated pituitary neurosurgeon and the use of selective adenomectomy as the preferred surgical approach wherever possible.

Polylactide-poly(ethylene glycol) micellar-like particles as potential drug carriers: production, colloidal properties and biological performance

The micellar-like particle systems produced from poly-D,L-lactide-poly(ethylene glycol) (PLA-PEG) copolymers have been assessed using a range of physicochemical characterisation methods, followed by in vivo studies of their biodistribution after intravenous administration to the rat. The size of the PEG chain was kept constant at 5 or 2 kDa, while the PLA size increased within a series from 2 to 25 kDa. The results obtained reveal, that in an aqueous medium the copolymers assembled into micellar-like structures, with the PLA segments forming the core and the PEG segments the surrounding corona. The size of the PLA segments dominated the process of assembly of the molecules and the characteristics of the resultant micellar-like particles. The PLA-PEG micellar particles were found to be less dynamic than those obtained from conventional surfactants. Particles formed from the lower molecular weight PLA polymers allowed a level of chain mobility while the cores of the micellar particles formed from higher molecular weight PLA appeared to be solid-like in nature. The size of the micellar particles was dependent on the copolymer molecular weight and the z-average diameter increased from 25 to 76 nm as the molecular weight of the PLA moiety increased. This provides an ability to control the particle size by adjusting the molecular weight of the PLA moiety. Following intravenous administration to the rat model, micellar-like particles smaller than approximately 70 nm accumulated in the liver, despite the fact that the PEG corona provided an effective steric stabilization effect. Micellar-like particles with a diameter of more than approximately 70 nm exhibited prolonged systemic circulation and reduced liver uptake, although the steric stabilisation of these particles was shown to be less effective. These findings agree with recent observations from other research groups; that indicate a possibility that very small particulates can pass through the sinusoidal fenestrations in the liver and gain access to the parenchymal cells of the liver.

Metabolism of sulfinpyrazone sulfide and sulfinpyrazone by human liver microsomes and cDNA-expressed cytochrome P450s

Human liver microsomes catalyze the oxidation of sulfinpyrazone sulfide (SPZS) to a variable mixture of sulfinpyrazone (SPZ) enantiomers and two minor phenolic metabolites. In one, the thiophenyl ring is hydroxylated, whereas in the second an N-phenyl ring is hydroxylated. SPZ is further oxidized to sulfinpyrazone sulfone (SPZO) and a minor polar metabolite that also has an N-phenyl ring hydroxylated. Determination of the metabolism of SPZ and SPZS under modified incubation conditions of prior heat treatment, higher pH, and the presence of detergent indicated that the formation of SPZ was cytochrome P450 (P450)- but not flavin monooxygenase-dependent. Specific P450 inhibitors (sulfaphenazole, quinidine sulfate, coumarin, diethyldithiocarbamic acid, troleandomycin, and furafylline) and specific cDNA-expressed P450s were used to identify the major isoforms responsible for the oxidation of SPZS to SPZ and SPZ to SPZO. Both P450 2C9 and P450 3A4 were responsible for the oxidation of SPZS to SPZ, whereas P450 3A4 alone catalyzed the further oxidation of SPZ to SPZO. SPZS was found to be metabolized by P450 2C9 to SPZ with a high degree of enantiomeric selectivity (9:1) and a K(m) comparable with its previously determined K(i) for inhibition of the P450 2C9-dependent 7-hydroxylation of (S)-warfarin (WARF). In contrast, the P450 3A4-catalyzed oxidation of SPZS to SPZ proceeded with the same enantioselectivity but to a much lesser degree (58:42). These results provide evidence that the metabolism of both (S)-WARF and SPZS is mediated by a common enzyme, P450 2C9, which is central to understanding the WARF-SPZ interaction and SPZS-mediated drug interactions in general.

Eating habits of children with autism

Autism is a developmental disorder characterized by severe deficits in social interaction and communication, as well as by stereotyped and repetitive behaviors. Children with autism frequently have significant eating difficulties with highly restricted range of food choices. Eating habits and patterns are often unusual and have an impact on family life. The purpose of this article was to review pertinent information regarding this complex developmental disorder and describe a recent study based on a parent survey of feeding patterns in children with autism to give a new perspective for both parents and professionals.

Implementation of a case coordinator role: a focused ethnographic study

This study was a focused ethnography of a 21-bed, inpatient psychiatric unit. Patient care was provided by a multidisciplinary team, and a case coordinator role was developed to coordinate the team's efforts. The purpose of the study was to describe perceptions of the implementation of the case coordinator role. Data collection methods included document review, participant and nonparticipant observation, and personal interviews of key informants. Field notes and transcriptions were analyzed throughout data collection. Three themes were identified: role development, role confusion, and role expectation. Role development was defined as the process of recognizing the need for and instituting the position of case coordinator. Role confusion was defined as the lack of a clear distinction between the role of the case coordinator and the role of the staff nurse. Role expectation was defined as the process of directing the development of the role based on individuals' perceptions of the role. Although the role as implemented had not met initial expectations, team members were confident the role would evolve to fulfill the unit's needs.

Pituitary apoplexy following metastasis of bronchogenic adenocarcinoma to a prolactinoma

A 42-year-old house wife presented with worsening headaches over 6 months in the absence of visual symptoms or symptoms suggestive of focal neurology. She was a life-long smoker. Systems review was unremarkable apart from secondary amenorrhoea and galactorrhoea of 6 months duration. Her serum prolactin was found to be 620 mU/l (60-400), FT4 12.6 nmol/l (9.8-23.1), TSH 1.38 mU/l (0.35-5.5), oestradiol < 73 pmol/l, LH and FSH of 4.4 and 12.6 mIU/l, respectively. She was on bromocriptine. A presumptive diagnosis of pneumonia, based on pyrexia and CXR findings, was made and she was started on IV antibiotics. Two days later she developed meningism and deterioration of conscious level. (Lumbar puncture results: no organisms, 312 neutrophils and 164 lymphocytes). CT scan revealed a 2.5-cm pituitary adenoma, with suprasellar extension. A repeat hormonal profile revealed FSH 1.4, LH < 0.3 mU/l, oestradiol < 73 pmol/l, prolactin 488 mU/l (60-400), and low random cortisol at 29 nmol/l. T1-weighted MRI revealed a large pituitary mass with evidence of haemorrhage. The patient subsequently underwent a transsphenoidal exploration with resection of the pituitary lesion. Whilst awaiting the histopathology results, CT of chest revealed a 1. 5-cm diameter rounded well defined density in the right lower lobe associated with hilar, pre- and right para-tracheal lymphadenopathy. The histopathology of the pituitary lesion, obtained piecemeal, revealed fragments of fibrous tissue infiltrated by sheets of acidophilic prolactin-positive cells, in keeping with a prolactinoma. In addition, other fragments with blood clot included highly atypical epithelial cells with mitotic figures. These were negative for prolactin but showed HMFG-and CEA-positivity, excluding them from a pituitary lineage. Transbronchial biopsy revealed moderately differentiated adenocarcinoma, with evidence of lymphatic spread. The overall conclusion was of bronchogenic adenocarcinoma, metastasizing to a prolactinoma and complicated by apoplexy.

Examination of low-incidence brain tumor responses in F344 rats following chemical exposures in National Toxicology Program carcinogenicity studies

Neoplasms in the brain are uncommon in control Fischer 344 (F344) rats; they occur at a rate of less than 1% in 2-yr toxicity/carcinogenicity studies. Furthermore, only 10 of nearly 500 studies conducted by the National Toxicology Program (NTP) showed any evidence of chemically related neoplastic effects in the brain. Generally, the brain tumor responses were considered equivocal, because the characteristics of potential neurocarcinogenic agents (such as statistically significant increased incidences, decreased latency and/or survival, and demonstration of dose-response relationships) were not observed. A thorough examination, including comparisons with a well-established historical database, is often critical in evaluating rare brain tumors. Chemicals that gave equivocal evidence of brain tumor responses were generally associated with carcinogenicity at other sites, and many chemicals were mutagenic when incubated with metabolic activating enzymes. Other factors that were supportive of the theory that marginal increases in brain tumor incidence were related to chemical exposure were that (a) some of the tumors were malignant, (b) no brain neoplasms were observed in concurrent controls from some studies, and/or (c) brain tumors were also seen following exposure to structurally related chemicals. In 2-yr studies in F344 rats (studies conducted by the NTP), equivocal evidence of carcinogenicity was observed for the following 9 chemicals: isoprene, bromoethane, chloroethane, 3,3'-dimethylbenzidine dihydrochloride, 3,3'-dimethoxybenzidine dihydrochloride, furosemide, C.I. direct blue 15, diphenhydramine hydrochloride, and 1-H-benzotriazole. Glycidol was the only chemical evaluated by the NTP with which there was clear evidence of brain tumor induction in F344 rats. Clarification of the potential neurocarcinogenic risks of chemicals that produce equivocal evidence of a brain tumor response in conventional 2-yr rodent studies may be aided by the use of transgenic mouse models that exhibit genetic alterations that reflect those present in human brain tumors as well as by the use of in utero exposures.

Plateletpheresis efficiency: a comparison of the spectra LRS and AMICUS separators

BACKGROUND

Optimizing the yields of plateletpheresis by increasing collection efficiencies may provide several benefits: to patients, by increasing the dose in single-donor platelet (SDP) units; to the collection center, by increasing the percentage of components that may be split into double units; and/or to the donor, by reducing the duration of donation.

STUDY DESIGN AND METHODS

A prospective, randomized study was undertaken to compare the efficiency of platelet collection in paired donations by 21 donors on two cell separators (Spectra LRS, version [v] 5.1; and AMICUS, v2.37). The order of donation was randomly assigned; donations were performed at least 2 weeks apart. A fixed blood volume (4000 mL) was processed by utilizing standard protocols. Findings were confirmed in a retrospective, matched study that compared the two separators by using fixed collection times (90 min).

RESULTS

The AMICUS and Spectra LRS separators consistently produced white cell-reduced (<1 x 10(6) white cells) components. The AMICUS harvested 32 percent more platelets on average (median, 4.9 x 10(11); range, 1.5-8.7 x 10(11)) than the Spectra LRS (median, 3.7 x 10(11); range, 2.1-7.7 x 10(11)) (p = 0.03), with mean times of 71.5 and 66.0 minutes (p = 0.03), respectively, to process 4000 mL. Mild donor reactions tended to be more common on the AMICUS separator, which used significantly more ACD (median 482 mL vs. 389 mL; p<0.0001) than on the Spectra LRS.

CONCLUSIONS

The AMICUS separator harvested more platelets per unit of blood volume processed than the Spectra LRS. Possible benefits include increased dose in each single-donor unit, increased double-unit harvests, and/or shorter donation time.

Posterior fossa epithelial cyst: case report and review of the literature

A 49-year old woman with progressive cranial nerve signs and hemiparesis was found at MR imaging and at surgery to have a cyst at the foramen magnum. Immunohistochemistry and electron microscopy showed an epithelial cyst of endodermal origin. MR findings were of an extraaxial mass, with short T1 and T2 times. Unless immunohistochemistry and electron microscopy are used in the final diagnosis of such cysts, all posterior fossa cysts lined by a single layer of epithelium should be described simply as epithelial cysts.

The butyrylcholinesterase K variant and susceptibility to Alzheimer's disease

Previous work has shown an association between the K variant of the butyrylcholinesterase (BCHE) gene and Alzheimer's disease (AD) in patients carrying the epsilon4 allele of ApoE. We attempted to replicate this finding in 181 UK white AD cases and 71 controls. No difference was found in BCHE-K genotypes (p=0.75) or alleles (p=0.70) between patients and controls. Moreover, despite a significant excess of ApoE epsilon4 in patients versus controls (p<0.0001), we found no evidence to support previous reports of an interaction between ApoE and BCHE-K (chi2=1.49, df=4, p=0.83).

Distribution and stability of antisense phosphorothioate oligonucleotides in rodent brain following direct intraparenchymal controlled-rate infusion

OBJECT

High-flow microinfusion is a novel technique for delivery of compounds directly into brain parenchyma, bypassing the blood-brain barrier. The feasibility of this technique has been demonstrated with low-molecular-weight compounds, macromolecular dyes, and proteins. Delivery of antisense oligonucleotides into brain parenchyma represents an additional potential application of this technique not previously described. In this report the authors sought to examine the distribution and disposition of phosphorothioate oligodeoxynucleotide (PS-ODN) for this reason.

METHODS

An 18-mer 35S-PS-ODN (Mr approximately 6000) was infused over 1 hour into the caudate putamen of Fischer 344 rats. At 1, 6, 12, 24, and 48 hours after beginning the infusion, the brains were extracted and analyzed using quantitative autoradiographic techniques. Cerebrospinal fluid (CSF) was also aspirated from the cisterna magna and was analyzed to determine the radioactivity and stability of the 35S-PS-ODN. At 1 hour, the infused ODN was uniformly distributed in brain tissue, with a maximum average concentration of 4806.5 +/- 210.5 nCi/g. This represents a tissue concentration of 19.2 +/- 0.84 microM. Extensive spread into surrounding parenchyma was observed over the ensuing 47 hours. The 35S-PS-ODN radioactivity peaked in the CSF at the end of the 1-hour infusion, containing 1% (50 +/- 20 nCi) of the infused radioactivity. Activity then decayed exponentially over 11 hours, but stabilized at a lower CSF content of 0.2% (1 +/- 0.1 nCi) thereafter. The volume of distribution was 105 +/- 7.9 mm3 at 1 hour, representing a volume of distribution/volume of infusion ratio of 5.2. The volume of distribution increased to 443 +/- 62.3 mm3 at the end of 48 hours, whereas the average minimum tissue concentration decreased from 15.2 microM to 3.2 microM. Undegraded 18-mer was observed throughout the 48-hour period by means of 20% polyacrylamide/7 M urea gel electrophoresis. The animals tolerated the infusion without evidence of toxicity and minimal structural changes in tissue were observed on histological investigation.

CONCLUSIONS

The authors found that PS-ODNs can be safely delivered in high concentrations to wide areas of rat brain by using high-flow microinfusion and are stable even after 48 hours in situ.