Abstract P1-19-02: Innovation in diagnosis and treatment of brain metastases using multifunctional nanomedicines

Systemic therapies have limited efficacy against brain metastases, largely because passive delivery of naked compounds via the bloodstream does not achieve sufficiently high or evenly dispersed intratumoural concentrations. Heterogeneous tissue architecture, abnormal perfusion, hypoxic zones and high interstitial fluid pressure are key factors limiting drug delivery, compounded by patchy blood-tumour-barrier permeability. Also, brain metastases are usually detected late, once patients become symptomatic. We are investigating whether engineered biopharmaceuticals might improve diagnostic sensitivity for earlier detection, as well as therapeutic efficacy and side-effect profiles of existing agents through active tumour targeting, delayed clearance and microenvironment-mediated activation. This study is proceeding with parallel preclinical and clinical tracks.

Preclinical aims: (1) Develop and characterise monoclonal antibody (mAb) fragments (scFvs) that target the brain metastasis markers HER2 and HER3; (2) Functionalise polyethylene glycol (PEG)-based nanocarriers with the scFvs, along with imaging agents to facilitate in vivoand ex vivoanalysis of tissue distribution; (3) Functionalise HER2/3-targeted carriers with doxorubicin via an acid-labile hydrazone bond for release in hypoxic environments, or the endosome compartment after internalization. Results to date. His-tagged HER2- and HER3-targeted scFvs based on ligand-binding sequences of clinically-approved mAbs were expressed and purified from Expi293 suspension cultures. Binding affinities are an order of magnitude stronger than parent mAbs (KD 2-8x10E-11M), determined using surface plasmon resonance analysis. The scFvs are cytostatic and moderately cytotoxic in vitro, with IC50s in order of 0.4-1.0μM. HER2 and HER3 scFvs exhibited dose-dependent, additive growth inhibition when used in combination, and induced internalisation of their receptor ligands within 4 hours in SKBr3 cells. Conclusions.The scFvs are strong carrier-tethering candidates in terms of both extracellular and intracellular payload release. Carrier synthesis is currently underway and preliminary in vivo data will be presented.

Clinical aims: (1) Develop and characterise 89Zirconium-labelled HER2-targeted PET tracers based on parent mAb and scFv; (2) Compare uptake and retention of the tracers in breast cancer patients with brain metastases; (3) Computationally relate tumour uptake to the administered dose, perfusion, tumour size and HER2 expression; (4) Determine the uptake range within and between patients, and the minimum size for reliable detection. Results to date. The mAb tracer has been synthesised, characterised and labelling processes scaled for clinical production. It is stable in physiologic conditions, retains HER2-binding activity and has a favourable biodistribution profile in NOD-SCID mice bearing BT474 xenografts. Conclusions. Australian regulatory approvals are in place and recruitment for the mAb imaging trial ("BoNSAI") has begun. Preliminary data will be presented.

Citation Format: Saunus JM, Lim M, Puttick S, Kalita-de Croft P, Houston ZH, Jones ML, Latter MJ, Campbell LC, Thomas P, Jeffree RL, Rose SE, Mahler SM, Thurecht KJ, Scott AM, Lakhani SR. Innovation in diagnosis and treatment of brain metastases using multifunctional nanomedicines [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-19-02.

Nitrate and nitrite in Australian leafy vegetables

A market survey of Australian leafy vegetables and a winter and spring experiment with Swiss chard were conducted to examine nitrate and nitrite levels in leaves. The relationship between growth response to nitrogen (N) supply and light level and accumulation of N in leaves was of particular interest. The survey that included 7 types of lettuce and endive (Asteraceae), 6 leafy Asian vegetables (Brassicaceae), and Swiss chard and spinach (Amaranthaceae) showed that fresh leafy vegetables available during a 6-month period on the Australian market can range in nitrate-N from 12 to 1400 mg/kg fresh weight and nitrite-N from 0 to 37.5 mg/kg. Some samples exceeded the limits for nitrate and nitrite based on international food safety standards. The response of Swiss chard to N supply and light was investigated. The accumulation of nitrate in Swiss chard was primarily influenced by increasing N supply and not by light level. Light conditions for all treatments in both the winter and spring experiments exceeded the critical level (~200 μmol/m2.s) required to increase leaf nitrate. Growth and leaf nitrate concentration were higher for spring, associated with average minimum to maximum temperatures of 18–39°C, compared with 14–28°C for winter. Treatment effects on nitrite-N in Swiss chard could not be determined because nitrite was only detected in one-third of plants. The importance of N supply in affecting nitrate accumulation in vegetables is highlighted by the Swiss chard experiments. It confirmed that nitrate accumulation occurs at optimal to supra-optimal nitrate supply, emphasising for growers the undesirable effect of excessive fertiliser use.

Electrophoretic manipulation of single DNA molecules in nanofabricated capillaries

We demonstrate the use of nanofabricated capillaries, integrated as part of a microfluidic structure, to study the electrophoretic behaviour of single, fluorescently-labelled, molecules of DNA as a function of capillary size. The nanocapillaries, fabricated using a focused ion beam, have cross-sections down to 150 x 180 nm. Control of single-molecule direction and velocity was achieved using voltage manipulation. DNA mobility was found to increase with decreasing cross-section, which we interpret in terms of reduced electro-osmotic counter-flow. Such nanofabricated capillaries as part of larger fluidic structures have great potential for biotechnology, particularly single molecule manipulation and analysis.

Somatic, affective, and pain characteristics of chronic TMD patients with sexual versus physical abuse histories

AIMS

This study examined whether temporomandibular disorder (TMD) patients with sexual versus physical abuse histories differ in their pain report, psychological distress, and somatic symptoms.

METHODS

Participants were 114 female TMD patients. The sample was divided into 3 groups based on abuse history: sexual abuse, physical abuse, or no abuse. Abuse histories were assessed with a structured clinical interview. Measures used included the McGill Pain Questionnaire, the State-Trait Anxiety Inventory, the Beck Depression Inventory, and the Pennebaker Inventory of Limbic Languidness. Group differences were analyzed by analysis of variance and Bonferroni post hoc comparisons.

RESULTS

Temporomandibular disorder patients with a history of physical abuse reported significantly more pain, anxiety, and depressive symptoms than did patients with a history of sexual abuse or no history of abuse. Furthermore, the results suggest that TMD patients with a sexual abuse history are not significantly different from patients with no abuse history across the domains studied.

CONCLUSION

Based on the differences found, it can be argued that assessment of physical abuse histories by appropriately trained clinicians should be a routine part of any multimodal assessment of female chronic TMD patients.

Trafficking of Glut4-green fluorescent protein chimaeras in 3T3-L1 adipocytes suggests distinct internalization mechanisms regulating cell surface glut4 levels

Insulin stimulates glucose transport in adipose and muscle tissue by stimulating the movement ('translocation') of an intracellular pool of glucose transporters (the Glut4 isoform) to the plasma membrane. We have engineered a series of chimaeras between Glut4 and green fluorescent protein (GFP) from Aequoria victoria and expressed these proteins in 3T3-L1 adipocytes by microinjection of plasmid cDNA. In the absence of insulin, GFP-Glut4 is localized intracellularly within a perinuclear compartment and multiple intracellular punctate structures. In response to insulin, chimaeric GFP-Glut4 species exhibit a profound redistribution to the cell surface with kinetics comparable with the endogenous protein. The intracellular localization of GFP-Glut4 overlaps partially with compartments labelled with Texas Red transferrin, but is largely distinct from intracellular structures identified using Lysotracker-Red(R). K(+)-depletion resulted in the accumulation of GFP-Glut4 at the cell surface, but to an lesser extent than that observed in response to insulin. In contrast with native Glut4, removal of the insulin stimulus or treatment of insulin-stimulated cells with phosphatidylinositol 3'-kinase inhibitors did not result in re-internalization of the chimaeric GFP-Glut4 from the plasma membrane, suggesting that the recycling properties of this species differ from the native Glut4 molecule. We suggest that the recycling pathway utilized by GFP-Glut4 in the absence of insulin is distinct from that used to internalize GFP-Glut4 from the plasma membrane after withdrawal of the insulin stimulus, which may reflect distinct pathways for internalization of endogenous Glut4 in the presence or absence of insulin.

Predicting treatment compliance following facial pain evaluation

The purpose of this study was to document compliance to treatment follow-up for facial pain patients referred for outside services. In addition, we generated a multidimensional model of the psychosocial constructs associated with chronic pain to determine whether these factors were predictive of compliance across recommended therapy modalities or with an overall measure of compliance. These constructs included pain report, depressive symptoms, anxiety, cognitive coping strategies, and physical activity reduction. The sample consisted of 80 facial pain patients evaluated at a tertiary care, facial pain clinic at a large university medical center. Compliance ratings ranged from 93% to 50% and are consistent with the literature that indicates that compliance differs across treatment modality. Furthermore, compliance rates were lower for the more nontraditional facial pain treatments performed by physical therapists or psychologists. Depression was negatively associated with compliance to medication changes, therapeutic injections, and splint therapy, but not psychological counseling or physical therapy. Increased pain was only associated with physical therapy. Measures of psychological distress (depression and anxiety) and pain were predictive of the overall measure of compliance. These results suggest that psychological distress can be a barrier for positive patient outcomes through reduced treatment compliance.

Neoadjuvant chemotherapy and radiotherapy for inoperable head and neck cancer: the LSU-Shreveport experience

A retrospective review of 8 years of treatment in 2 hospitals in Shreveport showed that neoadjuvant chemotherapy with radiotherapy was performed in 39 patients with inoperable, locally advanced head and neck cancer. Twenty-two individuals treated by definitive radiotherapy alone served as historical controls. The cumulative survival rate at 4 years was 34% in patients managed by neoadjuvant chemotherapy with radiotherapy and 7% in patients treated by radiotherapy only. With the exception of greater acute toxicity seen in patients receiving neoadjuvant chemotherapy with radiotherapy, differences in locoregional failure, distant metastasis, and late complication rates were not observed between the patient groups.

Compartment-ablation studies of GLUT4 distribution in adipocytes: evidence for multiple intracellular pools

The available data suggest that GLUT4 does populate the recycling endosomal system to some extent, but that a large proportion of the intracellular GLUT4 resides in a compartment that is devoid of transferrin receptors and may have properties more akin to specialized secretory vesicles. The study of the nature and biogenesis of this compartment will provide important insight into the mechanism by which insulin stimulates glucose transport. Further study of the role of the synaptobrevins in these distinct subcellular compartments will probably shed further light on the mechanism by which insulin stimulates GLUT4 translocation.

Transfusion therapy in sickle cell disease patients: methods and acute indications

Management of transfusion therapy in sickle cell disease patients with acute complications is often made difficult because of confusing indications, a variety of methods, disparate goals, and varying needs for maintenance transfusion. In priapism, acute chest syndrome, many major surgical procedures, toxemia of pregnancy, and cerebrovascular accidents, the target hemoglobin A level should be made as close to 100% as possible by mechanized red blood cell exchange. If mechanized exchange is unavailable, manual exchange should be instituted. Hemoglobin A should be maintained at greater than 60% to 70% by periodic simple transfusion until patients are fully recovered. Stroke patients should undergo maintenance transfusions for at least 3 years and perhaps 5 to 12 years. Physicians and patients should be aware of the transfusion-related risks of hepatitis and HIV infection. Alloimmunization and iron overload should be minimized in patients requiring frequent transfusions and chelation therapy should be utilized for iron overload.

Rainfall patterns in a major wheat-growing region of Australia

Rainfall is an important variable in the wheat production areas of Australia. This analysis examines, firstly, the pattern of rainfall over 2.3 million ha of a high-quality wheat-producing region, and secondly, develops regression equations for rainfall prediction over this region. Most of the variation in rainfall pattern across the region is accounted for by differences in October-to-March (summer) rainfall and in April-to-September (winter) rainfall. The summer rainfall differences account for over two thirds of the variation. Based on these two rainfall periods, a partitioning of the study area reveals five distinct regions. The second part of the analysis uses multiple regression to provide a set of equations for rainfall prediction at any location in the region, for a number of rainfall periods. These equations use altitude, longitude and latitude as predictors. Nearly all of the equations explain between 80% and 94% of the variation in rainfall. Differences between regions are accounted for in the analysis, making the equations widely applicable. The validity of the mean rainfall equations was tested on three further sites: the mean prediction error was 6.9%. This approach may be applicable where large land masses with similar geographical features occur.

Characteristics of frost in a major wheat-growing region of Australia

Frost at anthesis of wheat reduces grain set. Characteristics of frost in a large section of the wheat belt of one Australian state (N.S.W.) are described. Using cluster analysis, the region can be divided into four homogeneous areas according to five general characteristics of frost These characteristics are the mean Julian day of first and last frost, the mean number of frost days, the proportion of single-day frosts (days on which a frost did not occur on the following day) from August to October and the proportion of frost free periods from August to October of less than 5 days' duration. All these characteristics were found to,be closely related to altitude in all areas, but not to latitude or longitude. Within each area, regression equations were developed which explained at least 87% of the variation in four of the general characteristics. Thus, altitude appears to be a useful predictor for these characteristics. The validity of each equation was tested using three independent data sets. The mean percentage errors for the mean Julian day of first and last frost and the proportion of single-day frosts from August to October were 5, 5 and 8% respectively. Errors for the mean number of frost days and proportion of frost free periods from August to October of less than 5 days duration were approximately 7% for one site and approximately 20% for two other sites. The characteristics of frost in the period in which most winter crops flower are also described. The characteristics are the mean date of last heavy frost and last frost, and frost spells in each of August, September and October. In order to minimize risk from frost during anthesis and from high temperature and water stress during grain filling, this analysis suggests that anthesis should occur in early/mid September, late September/early October and early/mid October for the western, central and eastern parts of the region respectively. For areas in the north-eastern and south-eastern parts that are above 500 m, anthesis should occur mid/late October and early/mid November respectively. These analytical findings are consistent with field studies on wheat. A weak negative correlation between the first and the last frost is present in most of the sites of the region. This suggests that if in any particular year the first frost occurs earlier than its long-term mean, then the last frost tends to occur later than its long-term mean.

Comparison of three techniques on time to awakening, time to orientation and incidence of nausea and vomiting using alfentanil in balanced anesthesia in an outpatient surgical setting

Maximizing patient safety and comfort while minimizing adverse sequelae are continuing anesthetic challenges. The purpose of this study was to examine three anesthetic techniques utilizing alfentanil with regard to time to awakening, time to orientation and incidence of nausea and vomiting. Surgical procedures were limited to knee arthroscopy, laparoscopy and dental extractions. Unpremedicated ASA I/II outpatients (n = 74) between the ages of 18 and 59 were randomly assigned to one of three groups: Group I: alfentanil + 67% N2O + 33% O2 Group II: alfentanil + 67% N2O + 33% O2 + droperidol 0.015 mg/kg Group III: alfentanil + 100% O2 + 0.7% isoflurane Anesthesia was induced with alfentanil 40 micrograms/kg, atracurium 0.4 mg/kg, thiamylal 4 mg/kg and 100% O2 and was maintained according to group assignment. The anesthetic was supplemented as clinically indicated with incremental boluses of alfentanil 10 micrograms/kg. Upon completion of surgery, muscle relaxation was reversed with edrophonium 0.75 mg/kg and atropine 0.015 mg/kg. Analyses indicated that the three groups were comparable in terms of potentially confounding variables including gender, race, surgical procedure, age, percent of ideal body weight, case length and dose of alfentanil in micrograms/kg/hr. Time to awakening was significantly shorter in the two N2O groups by approximately 1.5 minutes, as compared to the O2 and isoflurane group (p = .0060). Time to orientation was significantly shorter in the N2O groups by approximately 1.5 minutes also, as compared to the O2 and isoflurane group (p = .0142). The two N2O groups did not differ significantly in either measure. The incidence of vomiting in the postanesthesia recovery room (PARR) indicated a significant difference (p = .0317) among groups with vomiting occurring 45.8% of the time in Group I, 28.8% of the time in Group II and 8% of the time in Group III. Total emetic score (nausea and vomiting) in the PARR indicated a significant difference (p = .03) among groups with symptoms occurring 50% of the time in Group I, 28% of the time in Group II, and 16% of the time in Group III.

Transport and distribution of manganese in two cultivars of soybean (Glycine max (L.) Merr.)

Transport and distribution patterns of manganese were studied in soybeans (cultivars Lee and Bragg) grown over a wide range of manganese supply levels in solution culture. Increasing the manganese supply from 1.8 �M to 450 .�M produced symptoms of manganese toxicity and reduced growth in both cultivars. Symptoms and dry matter yield reductions were more severe in Bragg. Manganese taken up by the plant was preferentially transported to young expanding tissue, while the amount moving to older tissue, including cotyledons, increased with availability. At high manganese supply the leaves accumulated higher concentrations with age, resulting in a decreasing concentration gradient between old and young leaves. There was no difference between Lee and Bragg in the distribution of manganese to plant parts or in the concentration of manganese in actively growing tissue. Manganese deficiency symptoms developed on both cultivars grown under limiting supply conditions. Partial mobility of the element was indicated: small amounts were translocated from the old leaves when young expanding leaves were manganese deficient. Nevertheless, considerable amounts remained in the cotyledons, and manganese appeared to have a low mobility when the plant's supply was limited.

Growth, yield components and seed composition of two soybean cultivars as affected by manganese supply

The influence of manganese nutrition on growth and yield of two soybean cultivars (Lee and Bragg) was studied in sand culture. Increasing the manganese concentration from 1.0�M to 275�M reduced vegetative growth and grain yield in both cultivars, the reduction being greater for Bragg than for Lee. The reduction in grain yield at high manganese levels resulted mainly from a reduced individual seed weight and a lower number of pods, with a slight reduction in the number of fertile nodes. There was no effect of high manganese supply on oil and protein levels or on the germination percentage of harvested seed. Manganese deficiency reduced vegetative growth, advanced flower initiation and pod formation, and decreased the grain yields of both cultivars. The reduced seed yield was mainly due to a reduction in the number of pods per plant and the individual seed weight. Manganese deficiency also reduced the concentration of oil in the seeds, but there was no effect on seed protein level or on the germination percentage cf harvested seed. Seed manganese concentration increased with the supply of the nutrient, but no difference in concentration was found between the two cultivars.

The response of plant mitochondria to media of high solute content

The state-3 rate of respiration of potato tuber mitochondria is inhibited by concentrations of KCl or NaCl above 125 mM, and by concentrations of sucrose, lactose, or maltose above 500 mM, but not at all by mannitol, glucose, glycine, or proline up to a concentration of 1500 mM in the medium. Mitochondria from cauliflower, beetroot, cucumber, rock melon, and watermelon behave very similarly to those from potato tuber. The variable response to different solutes proves that the reduction in respiration is not a simple function of the chemical potential of water in the medium. Disruption of potato mitochondria by ultrasonic vibration does not relieve the inhibition of succinate oxidation caused by KCl or sucrose. However, treatment with detergent abolishes completely the inhibition of respiration by sucrose. Inhibition of succinate dehydrogenase [Succinate:PMS, oxidoreductase (EC.1.3.99.1)] and malate dehydrogenase [L-Malate:NAD oxidoreductase (EC.1.1.1.37)] activities by sucrose is less than the inhibition of succinate- and malate-dependent oxygen uptake by the potato mitochondria. Limited substrate uptake and, alternatively, reduced electron flow as a consequence of a direct effect of solute on the mitochondrial membrane are considered as possible mechanisms of inhibition.