Biomanufacturing in low Earth orbit for regenerative medicine

Research in low Earth orbit (LEO) has become more accessible. The 2020 Biomanufacturing in Space Symposium reviewed space-based regenerative medicine research and discussed leveraging LEO to advance biomanufacturing for regenerative medicine applications. The symposium identified areas where financial investments could stimulate advancements overcoming technical barriers. Opportunities in disease modeling, stem-cell-derived products, and biofabrication were highlighted. The symposium will initiate a roadmap to a sustainable market for regenerative medicine biomanufacturing in space. This perspective summarizes the 2020 Biomanufacturing in Space Symposium, highlights key biomanufacturing opportunities in LEO, and lays the framework for a roadmap to regenerative medicine biomanufacturing in space.

Open-source Software Sustainability Models: Initial White Paper From the Informatics Technology for Cancer Research Sustainability and Industry Partnership Working Group

Background

The National Cancer Institute Informatics Technology for Cancer Research (ITCR) program provides a series of funding mechanisms to create an ecosystem of open-source software (OSS) that serves the needs of cancer research. As the ITCR ecosystem substantially grows, it faces the challenge of the long-term sustainability of the software being developed by ITCR grantees. To address this challenge, the ITCR sustainability and industry partnership working group (SIP-WG) was convened in 2019.

Objective

The charter of the SIP-WG is to investigate options to enhance the long-term sustainability of the OSS being developed by ITCR, in part by developing a collection of business model archetypes that can serve as sustainability plans for ITCR OSS development initiatives. The working group assembled models from the ITCR program, from other studies, and from the engagement of its extensive network of relationships with other organizations (eg, Chan Zuckerberg Initiative, Open Source Initiative, and Software Sustainability Institute) in support of this objective.

Methods

This paper reviews the existing sustainability models and describes 10 OSS use cases disseminated by the SIP-WG and others, including 3D Slicer, Bioconductor, Cytoscape, Globus, i2b2 (Informatics for Integrating Biology and the Bedside) and tranSMART, Insight Toolkit, Linux, Observational Health Data Sciences and Informatics tools, R, and REDCap (Research Electronic Data Capture), in 10 sustainability aspects: governance, documentation, code quality, support, ecosystem collaboration, security, legal, finance, marketing, and dependency hygiene.

Results

Information available to the public reveals that all 10 OSS have effective governance, comprehensive documentation, high code quality, reliable dependency hygiene, strong user and developer support, and active marketing. These OSS include a variety of licensing models (eg, general public license version 2, general public license version 3, Berkeley Software Distribution, and Apache 3) and financial models (eg, federal research funding, industry and membership support, and commercial support). However, detailed information on ecosystem collaboration and security is not publicly provided by most OSS.

Conclusions

We recommend 6 essential attributes for research software: alignment with unmet scientific needs, a dedicated development team, a vibrant user community, a feasible licensing model, a sustainable financial model, and effective product management. We also stress important actions to be considered in future ITCR activities that involve the discussion of the sustainability and licensing models for ITCR OSS, the establishment of a central library, the allocation of consulting resources to code quality control, ecosystem collaboration, security, and dependency hygiene.

Translating Dental, Oral, and Craniofacial Regenerative Medicine Innovations to the Clinic through Interdisciplinary Commercial Translation Architecture

Few university-based regenerative medicine innovations in the dental, oral, and craniofacial (DOC) space have been commercialized and affected clinical practice in the United States. An analysis of the commercial translation literature and National Institute for Dental and Craniofacial Research's (NIDCR's) portfolio identified barriers to commercial translation of university-based DOC innovations. To overcome these barriers, the NIDCR established the Dental Oral Craniofacial Tissue Regeneration Consortium. We provide generalized strategies to inform readers how to bridge the "valley of death" and more effectively translate DOC technologies from the research laboratory or early stage company environment to clinical trials and bring needed innovations to the clinic. Three valleys of death are covered: 1) from basic science to translational development, 2) from translational technology validation to new company formation (or licensing to an existing company), and 3) from new company formation to scaling toward commercialization. An adapted phase-gate model is presented to inform DOC regenerative medicine teams how to involve regulatory, manufacturability, intellectual property, competitive assessments, business models, and commercially oriented funding mechanisms earlier in the translational development process. An Industrial Partners Program describes how to conduct market assessments, industry maps, business development processes, and industry relationship management methods to sustain commercial translation through the later-stage valley of death. Paramount to successfully implementing these methods is the coordination and collaboration of interdisciplinary teams around specific commercial translation goals and objectives. We also provide several case studies for translational projects with an emphasis on how they addressed DOC biomaterials for tissue regeneration within a rigorous commercial translation development environment. These generalized strategies and methods support innovations within a university-based and early stage company-based translational development process, traversing the many funding gaps in dental, oral, and craniofacial regenerative medicine innovations. Although the focus is on shepherding technologies through the US Food and Drug Administration, the approaches are applicable worldwide.

Pressure Ulcer Monitoring Platform-A Prospective, Human Subject Clinical Study to Validate Patient Repositioning Monitoring Device to Prevent Pressure Ulcers

Objective: The objective of this prospective clinical study was to validate two prototype pressure ulcer monitoring platform (PUMP) devices, (PUMP1 and PUMP2), to promote optimal bed repositioning of hospitalized patients to prevent pressure ulcers (PUs). Approach: PUMP1 was a wearable electronic device attached to the patient gown with no skin contact. PUMP2 was a set of four identical electronic devices placed under the patient's bed wheels. A video camera recorded events in the patient room while measurements from the PUMP devices were correlated with true patient repositioning activity. The performance of these PUMP devices developed by our research team were evaluated and compared by both clinicians and engineers. Results: Ten mobility-restricted patients were enrolled into the study. Repositioning movement was recorded by both PUMP devices for 10 ± 2 h and corroborated with video capture. One hundred thirty-seven movements in total were detected by both PUMP1 and PUMP2 over 105 h of capture. Two false positives were detected by the sensors and 11 movements were missed by the sensors. PUMP1 and PUMP2 never conflicted in data collection. Innovation: The presented study evaluated two different sensors' abilities to capture accurate patient repositioning to eventually prevent PU formation. Importantly, detection of patient motion was completed without contact to patient skin. Conclusion: The clinical study demonstrated successful capture of patient repositioning movement by both PUMP1 and PUMP2 devices with 85% reliability, 2 false positives, and 11 missed movements. In future studies, the PUMP devices will be combined with a SMS-based mobile phone alert system to improve caregiver repositioning behavior.

Long-term control of olfactory neuroblastoma in a dog treated with surgery and radiation therapy

BACKGROUND

Olfactory neuroblastoma is a rare malignancy of the nasal cavity in dogs that is thought to arise from specialised sensory neuroendocrine olfactory cells derived from the neural crest.

CASE REPORT

An 8-year-old dog was presented for reclusiveness and pacing. On CT and MRI, a contract-enhancing mass was disclosed within the rostral fossa, extending caudally from the cribriform plate into the left nasal sinus. Surgical excision was performed and the diagnosis was histological grade III (Hyams grading scheme) olfactory neuroblastoma. Based on human CT criteria this was high stage (modified Kadish stage C). Surgical excision was incomplete and was followed by curative-intent radiation therapy using a linear accelerator to a total dose of 48 Gy.

CONCLUSION

The dog survived 20 months after diagnosis. Although olfactory neuroblastoma is a rare tumour in dogs, aggressive local therapy may allow for prolonged survival, even when the tumour is advanced.

Chemotherapy for dogs with lymph node metastasis from histiocytic sarcomas

BACKGROUND

Histiocytic sarcomas (HS) frequently metastasise, most commonly to visceral sites, but also to regional lymph nodes. Nodal metastases are associated with a poorer prognosis. This retrospective study aimed to evaluate prognostic factors, including the effect of adjuvant chemotherapy, on survival in dogs with nodal, but not systemic, metastases from HS.

METHODS

Retrospective case series of 12 dogs with histologically diagnosed HS metastatic to lymph nodes treated with surgery with and without adjuvant chemotherapy.

RESULTS

All dogs had histological evidence of metastasis to lymph nodes, with no clinical evidence for metastasis to viscera. Eight dogs that received chemotherapy had a median estimated survival of 219 days (range 77-1638 days); 1- and 2-year estimated survival rates were 37.7%. Median survival time for 4 dogs with nodal metastases that did not receive chemotherapy was 57 days (range 39-136 days) with none alive 1 year after surgery CONCLUSION: Survival for dogs with only regional nodal metastases from HS appeared to be improved by adjuvant chemotherapy.

Improved Transplanted Stem Cell Survival in a Polymer Gel Supplemented With Tenascin C Accelerates Healing and Reduces Scarring of Murine Skin Wounds

Mesenchymal stem cells (MSCs) remain of great interest in regenerative medicine because of their ability to home to sites of injury, differentiate into a variety of relevant lineages, and modulate inflammation and angiogenesis through paracrine activity. Many studies have found that despite the promise of MSC therapy, cell survival upon implant is highly limited and greatly reduces the therapeutic utility of MSCs. The matrikine tenascin C, a protein expressed often at the edges of a healing wound, contains unique EGF-like repeats that are able to bind EGFR at low affinities and induce downstream prosurvival signaling without inducing receptor internalization. In this study, we utilized tenascin C in a collagen/GAG-based polymer (TPolymer) that has been shown to be beneficial for skin wound healing, incorporating human MSCs into the polymer prior to application to mouse punch biopsy wound beds. We found that the TPolymer was able to promote MSC survival for 21 days in vivo, leading to associated improvements in wound healing such as dermal maturation and collagen content. This was most marked in a model of hypertrophic scarring, in which the scar formation was limited. This approach also reduced the inflammatory response in the wound bed, limiting CD3e+ cell invasion by approximately 50% in the early wound-healing process, while increasing the numbers of endothelial cells during the first week of wound healing as well. Ultimately, this matrikine-based approach to improving MSC survival may be of great use across a variety of cell therapies utilizing matrices as delivery vehicles for cells.

Abstract P1-07-01: Modeling breast cancer dormancy and re-emergence

Most breast cancer (BrCa) mortality results from distant metastases. Current evidence strongly suggests that in some instances these disseminated cells remain dormant for long periods of time. Both the non-proliferative state and protective microenvironment of the metastatic niche likely contribute to the observed resistance of metastases to chemotherapies that are otherwise effective against the primary tumor. Although significant interventional progress has been made on primary tumors, the lack of relevant accessible model systems for metastases has hindered the development of therapies against this stage. To address this gap, we developed an innovative all-human 3D ex vivo hepatic microphysiological system (MPS) to faithfully reproduce human physiology and thereby facilitate the investigation of BrCa behavior in a micrometastatic niche. The liver is a major site of metastasis for carcinomas and is also the primary site of drug metabolism (activation and/or detoxification), which is a significant factor in determining efficacy and limiting toxicities of cancer therapies.

The MPS incorporates hepatocytes and nonparenchymal cells (NPC) isolated from fresh human liver resections. BrCa cells (RFP+) are seeded on day 3 and afforded time to intercalate into the hepatic tissue until treatment with chemotherapy on day 7 for 72h. Surviving BrCa cells are stimulated on day 13 with LPS/EGF and cultured through day 15. Proliferation is monitored by RFP quantification, Ki67 staining and EdU incorporation. Physiological function of the hepatic tissue is monitored throughout the experiment by protein catabolism (urea), active metabolism (glucose, CYP P450) and injury markers (AST, ALT, A1AT, fibrinogen). Luminex assays (55 analytes) were used to provide insights into the communication networks in the hepatic metastatic milieu during different stages of dormancy and progression, and identify potential metastatic biomarkers via computational approaches.

The MPS maintains the physiologic function of the hepatic niche through 15 days and BrCa cells effectively integrate into the established niche. Spontaneous dormancy is observed amongst a subpopulation of BrCa cells, indicated by the absence of Ki67 staining and EdU incorporation after 12 days of culture. Further, we demonstrate that the BrCa cells surviving chemotherapy (doxorubicin) are non-proliferating (Ki67-/EdU-). Notably, ‘re-awakening’ of the surviving non-proliferating cancer cells is observed in the presence of physiological inflammatory stressors (LPS/EGF). Luminex analyses of the milieu effluent identified signaling molecules from NPC influenced the metastatic cell fraction entering dormancy.

This MPS provides unprecedented insights into the tumor biology of dormant micrometastases. We demonstrate the recreation of spontaneous, rather than engineered, BrCa dormancy in an all-human ex vivo hepatic MPS. Mimicking the dormancy and outgrowth observed in patients, we found that dormant breast cancer cells that are resistant to chemotherapy can be stimulated to re-emerge following an inflammatory insult. Ultimately, this MPS provides an accessible tool to identify new therapeutic strategies for metastasis during initial seeding, dormancy and re-emergence, while concurrently evaluating agent efficacy for metastasis, metabolism and dose-limiting toxicity.

Citation Format: Amanda M Clark, Sarah E Wheeler, Donald P Taylor, Carissa L Young, Venkateswaran C Pillai, Donna B Stolz, Raman Venkataramanan, Douglas A Lauffenburger, Linda G Griffith, Alan Wells. Modeling breast cancer dormancy and re-emergence [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-07-01.

Spontaneous dormancy of metastatic breast cancer cells in an all human liver microphysiologic system

Background:

Metastatic outgrowth in breast cancer can occur years after a seeming cure. Existing model systems of dormancy are limited as they do not recapitulate human metastatic dormancy without exogenous manipulations and are unable to query early events of micrometastases.

Methods:

Here, we describe a human ex vivo hepatic microphysiologic system. The system is established with fresh human hepatocytes and non-parenchymal cells (NPCs) creating a microenvironment into which breast cancer cells (MCF7 and MDA-MB-231) are added.

Results:

The hepatic tissue maintains function through 15 days as verified by liver-specific protein production and drug metabolism assays. The NPCs form an integral part of the hepatic niche, demonstrated within the system through their participation in differential signalling cascades and cancer cell outcomes. Breast cancer cells intercalate into the hepatic niche without interfering with hepatocyte function. Examination of cancer cells demonstrated that a significant subset enter a quiescent state of dormancy as shown by lack of cell cycling (EdU⁻ or Ki67⁻). The presence of NPCs altered the cancer cell fraction entering quiescence, and lead to differential cytokine profiles in the microenvironment effluent.

Conclusions:

These findings establish the liver microphysiologic system as a relevant model for the study of breast cancer metastases and entry into dormancy.

A microphysiological system model of therapy for liver micrometastases

Metastasis accounts for almost 90% of cancer-associated mortality. The effectiveness of cancer therapeutics is limited by the protective microenvironment of the metastatic niche and consequently these disseminated tumors remain incurable. Metastatic disease progression continues to be poorly understood due to the lack of appropriate model systems. To address this gap in understanding, we propose an all-human microphysiological system that facilitates the investigation of cancer behavior in the liver metastatic niche. This existing LiverChip is a 3D-system modeling the hepatic niche; it incorporates a full complement of human parenchymal and non-parenchymal cells and effectively recapitulates micrometastases. Moreover, this system allows real-time monitoring of micrometastasis and assessment of human-specific signaling. It is being utilized to further our understanding of the efficacy of chemotherapeutics by examining the activity of established and novel agents on micrometastases under conditions replicating diurnal variations in hormones, nutrients and mild inflammatory states using programmable microdispensers. These inputs affect the cues that govern tumor cell responses. Three critical signaling groups are targeted: the glucose/insulin responses, the stress hormone cortisol and the gut microbiome in relation to inflammatory cues. Currently, the system sustains functioning hepatocytes for a minimum of 15 days; confirmed by monitoring hepatic function (urea, α-1-antitrypsin, fibrinogen, and cytochrome P450) and injury (AST and ALT). Breast cancer cell lines effectively integrate into the hepatic niche without detectable disruption to tissue, and preliminary evidence suggests growth attenuation amongst a subpopulation of breast cancer cells. xMAP technology combined with systems biology modeling are also employed to evaluate cellular crosstalk and illustrate communication networks in the early microenvironment of micrometastases. This model is anticipated to identify new therapeutic strategies for metastasis by elucidating the paracrine effects between the hepatic and metastatic cells, while concurrently evaluating agent efficacy for metastasis, metabolism and tolerability.

Abstract P5-04-08: Modeling breast cancer dormancy

Most cancer mortality results from distant metastases. The metastatic microenvironment protects ectopic tumors, these nodules are often resistant to agents that eradicate the primary mass. Although significant interventional progress has been made on primary tumors, the lack of relevant accessible model in vitro systems in which to study metastases has plagued metastatic therapeutic development – particularly among micrometastases. One third of women diagnosed with breast cancer (BC) will have metastatic disease which often presents years after a seeming cure from the primary malignancy. An in silico model of micrometastases strongly suggests that these disseminated cells are quiescent, or ‘dormant’, for long periods of time. Current models fail to recapitulate metastatic dormancy, in vivo due to issues of spontaneous metastases and rodent lifespan and in vitro due to the nascent state of organotypic organs or microphysiological systems (MPS). We hypothesize that even the most developed MPS do not allow tumors to attain dormancy due to continued stress signaling from stiff matrices and an artificial microenvironment. We use an innovative all human three dimensional liver MPS to faithfully reproduce human physiology and pathology. In the initial iteration, the liver cells are isolated from therapeutic partial hepatectomies, but as this source may be limiting, we are examining induced pluripotent stem cells (iPSC). Currently these iPSC-derived hepatocyte-like cells demonstrate cyp p450 activity and production of fibrinogen and urea through 15 days in our MPS, albeit at levels below fresh human hepatocytes; optimization protocols are underway.

In the first phase of this work we optimized the flow rate and seeding of hepatocytes with non-parenchymal cells (NPCs) from fresh human liver resections. We found that higher flow rates produced poorer tissue formation and increased stress fibers/actin filaments. We maintained functioning hepatocytes in the MPS through 15 days. Hepatocyte function and injury was measured by urea, lactate, AST, ALT, A1AT, fibrinogen and cyp p450 assays. NPCs survived through the 15 day endpoint with immunofluorescent microscopy visualizing leukocytes, endothelial cells and macrophages. The proliferative MDA MB 231 BC cell line showed preliminary evidence of growth attenuation after 12 days of culture in a subpopulation of cells in our MPS. Luminex cancer panel studies are underway with systems biology modeling to describe a communication network in the early microenvironment of micrometastases.

In parallel we are piloting hydrogel scaffolds that support tissue formation but provide a more physiologic rheology; stiff supporting materials yield an inflammatory phenotype in the NPC which forces even well-differentiated BC cells towards a mesenchymal phenotype. We found that hydrogels support hepatocytes through 15 days and incorporate cancer cells. Micropumps are also being developed by Draper Laboratories to allow for physiologic diurnal variations of hormones and nutrients to liver tissues to accurately assess dormancy and chemotherapy response. The completion of these studies will provide insights into the tumor biology of dormant micrometastases and an accessible tool for testing of therapeutics against metastatic BC in a metabolically competent system.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-04-08.

The dormancy dilemma: quiescence versus balanced proliferation

Metastatic dissemination with subsequent clinical outgrowth leads to the greatest part of morbidity and mortality from most solid tumors. Even more daunting is that many of these metastatic deposits silently lie undetected, recurring years to decades after primary tumor extirpation by surgery or radiation (termed metastatic dormancy). As primary tumors are frequently curable, a critical focus now turns to preventing the lethal emergence from metastatic dormancy. Current carcinoma treatments include adjuvant therapy intended to kill the cryptic metastatic tumor cells. Because such standard therapies mainly kill cycling cells, this approach carries an implicit assumption that metastatic cells are in the mitogenic cycle. Thus, the pivotal question arises as to whether clinically occult micrometastases survive in a state of balanced proliferation and death, or whether these cells undergo at least long periods of quiescence marked by cell-cycle arrest. The treatment implications are thus obvious--if the carcinoma cells are cycling then therapies should target cycling cells, whereas if cells are quiescent then therapies should either maintain dormancy or be toxic to dormant cells. Because this distinction is paramount to rational therapeutic development and administration, we investigated whether quiescence or balanced proliferation is the most likely etiology underlying metastatic dormancy. We recently published a computer simulation study that determined that balanced proliferation is not the likely driving force and that quiescence most likely participates in metastatic dormancy. As such, a greater emphasis on developing diagnostics and therapeutics for quiescent carcinomas is needed.

Abstract 1094: Breast cancer metastatic competency in the hepatic niche is driven by E-cadherin re-expression

Nearly half of breast cancer metastases will become clinically evident 5 or more years after the cancer was seemingly ablated. This implies that metastatic cancer cells survived over this extended timeframe without emerging as detectable nodules. Breast cancer metastatic dormancy has yet to be universally defined, and is not well understood as a potential means by which clinically evident metastases emerge after being undetected for years (or decades) from the primary tumor diagnosis. Various mechanistic and microenvironmental factors may work independently, collaboratively (or both) in order to allow a dormant metastatic breast cancer cell (or small cluster) to survive long term. At least one tumor dormancy hallmark is likely required: that of E-cadherin re-expression in order to form heterotypic connections between the carcinoma cells and the liver parenchyma. This re-expression is known as the mesenchymal-to-epithelial-reverting-transition (MErT). This re-expression provides not only survival signals to the breast cancer cells but may also establish cell polarity and protection from autocrine signaling (or extracellular factors) that otherwise may prompt the breast cancer cells to initiate metastatic outgrowth.

The purpose of this study is to determine E-cadherin's function in the establishment of breast cancer metastases to the liver. The MDA-MB-231 human breast cancer cell line, that can undergo induced MErT ex vivo, was transfected with either exogenously expressing E-cadherin or shRNA to E-cadherin. Xenograft splenic injections of these cell line variants into mice were performed and tumors allowed to grow for 30-60 days until sacrifice. Immunohistochemistry was performed on the liver and splenic tissue sections in order to assess the number and size of metastatic depostis. Preliminary data demonstrate that cells expressing exogenously encoded E-cadherin developed large splenic tumors with fewer to no liver metastases. MDA-MB-231 wild type cells spawned liver metastases about half the time. In order to more fully probe E-cadherin's role in metastatic competency experiments are underway to develop a doxycycline-inducible E-cadherin bicistronic vector allowing for the down-regulation of E-cadherin in the primary tumor and the re-expression in the metastatic niche. Subsequent immunohistochemistry will determine the metastatic E-cadherin status across these MDA-MB-231 cell variants. These results will provide insights into the role of MErT in metastatic establishment.

Citation Format: Donald P. Taylor. Breast cancer metastatic competency in the hepatic niche is driven by E-cadherin re-expression. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1094. doi:10.1158/1538-7445.AM2013-1094

Abstract C93: Liver nonparenchymal cells drive metastatic breast cancer survival but fail to initiate mesenchymal to epithelial reversion

Nearly half of breast cancer metastases will become clinically evident 5 or more years after the cancer was seemingly ablated. This implies that metastatic cancer cells survived over this extended timeframe without emerging as detectable nodules. Breast cancer metastatic dormancy has yet to be universally defined, and is not well understood as a potential means by which clinically evident metastases emerge after being undetected for years (or decades) from the primary tumor diagnosis. Various mechanistic and microenvironmental factors may work independently, collaboratively (or both) in order to allow a dormant metastatic breast cancer cell (or small cluster) to survive long term. At least one tumor dormancy hallmark is likely required: that of E-cadherin re-expression in order to form heterotypic connections between the carcinoma cells and the liver parenchyma. This re-expression is known as the mesenchymal-to-epithelial-reverting-transition (MErT). This re-expression provides not only survival signals to the breast cancer cells but may also establish cell polarity and protection from autocrine signaling (or extracellular factors) that otherwise may prompt the breast cancer cells to initiate metastatic outgrowth.

The purpose of this study was to determine whether non-parenchymal liver cells (NPC) contribute to metastatic competency, initiate mesenchymal to epithelial reverting transition (MErT), and trigger metastatic dormancy. We co-cultured human or rat hepatic isolations with highly metastatic human immortalized breast cancer cells (MDA-MB-231). The hepatocytes, non-parenchymal hepatic supernatant, and liver sinusoidal endothelial cell enriched populations were independently cultured with the breast cancer cells in standard monolayer cultures. Because MDA-MB-231 cells do not survive in the hepatocyte culture media alone, we were able to assess the unique properties imparted by the experimental cultures. Confocal immunofluorescent imaging for proliferation and epithelial markers revealed a mesenchymal phenotypic transition only in the hepatocyte/breast cancer cultures. Interestingly the NPC/breast cancer co-cultures promoted cancer cell proliferation (but lower than with hepatocytes included) but did not impart carcinoma epithelial reversion. The liver sinusoidal endothelial cell (LSEC)-enriched co-cultures exhibited much lower breast cancer cell proliferation hinting toward a possible dormancy, though E-cadherin reversion was not detected. These data suggest that perturbations of the parenchymal and non-parenchymal cell ratios in the liver metastatic microenvironment may contribute to metastatic dormancy initiation or stability.

Citation Format: Donald P. Taylor, Alan Wells. Liver nonparenchymal cells drive metastatic breast cancer survival but fail to initiate mesenchymal to epithelial reversion. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C93.

Modeling boundary conditions for balanced proliferation in metastatic latency

PURPOSE

Nearly half of cancer metastases become clinically evident five or more years after primary tumor treatment; thus, metastatic cells survived without emerging for extended periods. This dormancy has been explained by at least two countervailing scenarios: cellular quiescence and balanced proliferation; these entail dichotomous mechanistic etiologies. To examine the boundary parameters for balanced proliferation, we conducted in silico modeling.

EXPERIMENTAL DESIGN

To illuminate the balanced proliferation hypothesis, we explored the specific boundary probabilities under which proliferating micrometastases would remain dormant. A two-state Markov chain Monte Carlo model simulated micrometastatic proliferation and death according to stochastic survival probabilities. We varied these probabilities across 100 simulated patients each with 1,000 metastatic deposits and documented whether the micrometastases exceeded one million cells, died out, or remained dormant (survived 1,218 generations).

RESULTS

The simulations revealed a narrow survival probability window (49.7-50.8%) that allowed for dormancy across a range of starting cell numbers, and even then for only a small fraction of micrometastases. The majority of micrometastases died out quickly even at survival probabilities that led to rapid emergence of a subset of micrometastases. Within dormant metastases, cell populations depended sensitively on small survival probability increments.

CONCLUSIONS

Metastatic dormancy as explained solely by balanced proliferation is bounded by very tight survival probabilities. Considering the far larger survival variability thought to attend fluxing microenvironments, it is more probable that these micrometastatic nodules undergo at least periods of quiescence rather than exclusively being controlled by balanced proliferation.

Abstract 5240: Breast cancer in the metastatic niche: A role for stress-induced dormancy

Breast cancer dormancy in the metastatic site allows tumors to avoid clinical detection and evade treatment leading to recurrence after years or decades, with devastating mortality rates. How the aggressive carcinoma cells that initially underwent a cancer-associated Epithelial to Mesenchymal Transition (EMT) from the primary tumor to disseminate and maintain a long-term dormant state in an ectopic site is unknown. We have found that normal parenchymal cells of certain metastatic organs cause a partial reversion of the EMT to a more epithelial phenotype (Mesenchymal to Epithelial Reversion Transition, or MErT). Compared to carcinoma cells in the primary breast tumor, MErT is characterized by increased E-cadherin expression, MAPK and AKT signaling, and chemoresistance. While this phenotype should reflect low proliferation or quiescence, the MErT cells in vitro have heretofore maintained a highly proliferative state. Herein we demonstrate that a pre-stressed hepatic microenvironment allows for EMT cells to increase their MErT phenotype and to become dormant. Our research strategy is to modulate the initial liver stress through biochemical challenges applied to primary rat hepatocytes co-cultured with hepatic resident cells and a human immortalized breast cancer cell line (MDA-MB-231). Biochemical challenges (e.g. TGFβ, TNFα, IL-6, EGF, HGF, and DAMPS) are applied in varying concentrations and incubation periods in order to pre-stress the hepatic culture. In order to maintain hepatic metabolic function we implement a novel 3D perfused micro-well bioreactor. As a secondary aim we explore whether E-cadherin expression is required for metastatic seeding through splenetic injections in immune compromised mice. We aim to uncover novel targets that are not strictly against the cancer cells, but rather, against shared molecular pathways across cancer, parenchymal, and non-parenchymal cells within the hepatic niche. Sustaining and perhaps enhancing the ectopic site resilience may yield therapies directed toward maintaining dormant carcinomas so that secondary EMTs will be blocked and cancer recurrence greatly reduced.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5240. doi:1538-7445.AM2012-5240

Amniotic membrane transplantation for corneal surface reconstruction after excision of corneolimbal squamous cell carcinomas in nine horses

OBJECTIVE

The purpose of this study was to evaluate the usefulness and effectiveness of permanent amniotic membrane transplantation as an adjunctive treatment to superficial keratectomy alone or combined with strontium-90 irradiation for treatment of equine corneolimbal squamous cell carcinoma (SCC) to decrease corneal scarring and recurrence rate.

STUDY

The retrospective case study included 11 horses (n = 12 eyes) diagnosed and treated for ocular SCC that involved the limbus and cornea. Nine of those horses (n = 9 eyes) were treated between 2002 and 2006, with superficial lamellar keratectomy alone or combined with strontium-90 irradiation and followed by placement of a permanent amniotic membrane graft in the surgical defect. The level of scarring (i.e. the clarity of the cornea) resulting with the use of amniotic membrane was subjectively compared to cases where a permanent bulbar conjunctival graft was performed following keratectomy combined with strontium-90 irradiation or cryotherapy (n = 3 eyes). Recurrence was defined as the postoperative and postirradiation regrowth of SCC in the same site and globe.

RESULTS

The nine horses that received an amniotic membrane graft after keratectomy alone or combined with irradiation showed a minimal level of scarring in a cornea that regained a greater transparency in comparison to the horses that were treated with a bulbar conjunctival graft. All of the horses that received an amniotic membrane graft had 226 +/- 218 days of follow-up without tumor recurrence (mean +/- SD), ranging from 21 days to 778 days.

CONCLUSIONS

The combination of superficial keratectomy alone or associated with beta-irradiation and permanent amniotic membrane transplantation is an effective treatment of corneal or corneolimbal SCC in horses. The placement of an amniotic membrane material represents an alternative surgical procedure to bulbar conjunctival grafts, especially if there is a lack of bulbar conjunctiva tissue available after tumor resection or if a particularly large corneal resection is necessary. The amniotic membrane is incorporated into the corneal defect and seems to create noticeably much less scarring than a corneal defect covered by bulbar conjunctiva.

An integrated biomedical knowledge extraction and analysis platform: using federated search and document clustering technology

High content screening (HCS) requires time-consuming and often complex iterative information retrieval and assessment approaches to optimally conduct drug discovery programs and biomedical research. Pre- and post-HCS experimentation both require the retrieval of information from public as well as proprietary literature in addition to structured information assets such as compound libraries and projects databases. Unfortunately, this information is typically scattered across a plethora of proprietary bioinformatics tools and databases and public domain sources. Consequently, single search requests must be presented to each information repository, forcing the results to be manually integrated for a meaningful result set. Furthermore, these bioinformatics tools and data repositories are becoming increasingly complex to use; typically they fail to allow for more natural query interfaces. Vivisimo has developed an enterprise software platform to bridge disparate silos of information. The platform automatically categorizes search results into descriptive folders without the use of taxonomies to drive the categorization. A new approach to information retrieval for HCS experimentation is proposed.

Induction of parturition in dairy cattle and its effects on health and subsequent lactation and reproductive performance

OBJECTIVE

To determine the effect of induction of parturition on health, milk production and reproductive performance of dairy cows.

DESIGN

A prospective cohort study in 62 dairy herds.

PROCEDURE

Health, milk production and fertility indices were documented for 1449 dairy cows treated with dexamethasone trimethylacetate, with or without prostaglandin to induce calving. Equivalent data was collected for 603 untreated herd mates that calved at approximately the same time.

RESULTS

The median interval from initial treatment to calving was 11 days. Induction was associated with a substantially lower calf survival and commercial value of surviving calves. Calf viability and value was lower when induced cows were at an earlier stage of pregnancy. Retained foetal membranes, photosensitisation and other problems were significantly more frequent in the induced group compared to the untreated group. Milk production of induced cows was approximately 4% lower than untreated ones, but the majority of reproductive indices were not significantly different between the two groups.

CONCLUSIONS

The practice of induction of parturition in seasonal calving dairy herds is a reliable way of shortening the gestation period of cows. Costs associated with morbidity and mortality of induced cows and losses in lactation and calf production are offset by benefits of improved reproductive performance and more efficient management of the herd. The welfare aspects of induction on calf survival must be considered.

Synthesis and biological characterization of .alpha.-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazinebutanol and analogs as potential atypical antipsychotic agents

A series of 1-(pyrimidin-2-yl)piperazine derivatives were prepared and evaluated in receptor binding assays and in in vivo behavioral paradigms as potential atypical antipsychotic agents. Compound 16 (BMS 181100 (formerly BMY 14802)) emerged as the lead compound from within the series on the basis of its good activity and duration of action in the inhibition of both conditioned avoidance responding and apomorphine-induced stereotopy in the rat. Compound 16 not only failed to induce catalepsy in the rat but was quite effective in reversing the cataleptic effect of neuroleptic agents, thus indicating a low propensity for causing extrapyramidal side effects. In comparison to reference antipsychotic agents, 16 appeared to be less sedating and was relatively weaker in causing muscle incoordination. The compound was essentially inactive in binding to dopamine D2 receptors and its chronic administration to rats did not result in dopamine receptor supersensitivity. It exhibited modest to weak affinity for 5-HT1A and alpha 1 receptors but was found to be a fairly potent ligand for sigma binding sites (IC50 vs (+)-[3H]-3-PPP = 112 nM). Although the resolved enantiomers of racemic 16 did not show dramatic differences from racemate or from each other in most tests, the R(+) enantiomer was up to 11-fold more potent than its antipode in binding to sigma sites. Several studies have indicated that 16 may be a limbic-selective agent which may modulate dopaminergic activity by an indirect mechanism. The compound has been selected for clinical evaluation in the treatment of psychosis.

Buspirone: an anxioselective alternative for the management of anxiety disorders

Buspirone HCl (Buspar) is a novel anxiolytic agent unrelated to the benzodiazepines or other psychotherapeutic agents. Animal studies support an anxioselective profile, i.e. relief of anxiety without sedation, muscle relaxation or anticonvulsant activity. Double-blind clinical studies show buspirone to be effective in the treatment of anxiety and anxiety in the presence of depression. The effects of buspirone on psychomotor function, physical dependence and abuse potential tests are similar to those seen with placebo treatments. Mechanism of action studies indicate activity in a variety of neuronal systems.

Discriminative stimulus characteristics of BMY 14802 in the pigeon

Pigeons were trained to discriminate intramuscular injections of 5.6 mg/kg BMY 14802, a drug that has relatively high affinity for sigma binding sites, from saline in a two-key operant procedure. Many compounds that displace sigma binding failed to produce BMY 14802-like discriminative stimulus effects; these included (+)-SKF 10,047, (+)3-PPP, DTG and MR 2035; the typical antipsychotic haloperidol; the putative antipsychotics tiospirone, cinuperone and rimcazole; and the uncompetitive NMDA antagonist phencyclidine. In addition, MR 2035 and tiosperone failed to antagonize the discriminative stimulus effects of BMY 14802. The selective D2 antagonist eticlopride and the norepinephrine uptake blocker and antidepressant desmethylimipramine also failed to evoke substantial BMY 14802-appropriate responding. In contrast to sigma ligands and other reference compounds, the 5-HT1A agonists buspirone, 8-OH-DPAT and spiroxatrine dose-dependently produced BMY 14802-like discriminative stimulus effects. The limited-efficacy 5-hydroxytryptamine (HT)1A agonist NAN 190 did not produce BMY 14802-like discriminative effects; however, it did competitively antagonize the stimulus effects of BMY 14802 and the BMY 14802-like stimulus effects of (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin. Other serotonergic compounds failed to produce substantial BMY 14802-appropriate responding; such as 5-HT1 agonist I-5-HTP; 5-HT1A/1B agonist RU24969; 5-HT1B/1C agonist m-CPP; 5-HT1C/2 agonist quipazine; 5-HT1C/2 antagonists, metergoline and the atypical antipsychotic clozapine; and 5-HT3 antagonist ondansetron. Also, metergoline, ondansetron and pirenpirone failed to antagonize the stimulus effects of BMY 14802. These results indicate that the discriminative stimulus effects of BMY 14802 are serotonergically mediated primarily by 5-HT1A receptors rather than by sigma sites.

An information infrastructure for long-term care

Emerging trends promise to alter the way long-term care is practiced. These include: changing regulation of the nursing home industry with emphasis on outcome and assessment, a trend in medical informatics away from expert systems and toward on-line decision support and reminder systems, and the application of industrial statistical quality management techniques to the realm of human services. Emerging standards such as the Arden Syntax and Unified Medical Language Systems and technologies such as Rapid Application Development Tools will facilitate the use of modern computing to mold and implement these converging trends.

Traceable values for nitrate in water samples by isotope dilution analysis using a small thermionic quadrupole mass spectrometer

An isotope dilution mass spectrometric procedure was developed for the determination of nitrate in water samples. The isotope dilution experiments were carried out using the Institute for Reference Materials and Measurements's 15N-enriched nitrate spike reference material IRMM-627. Nitrate was isolated from the matrix by precipitating it as nitron nitrate, from which emission of negative thermal NO2-ions was found to be best. The ions were produced in the ion source of a small, low-cost, easy-to-handle thermionic quadrupole mass spectrometer equipped with a secondary electron multiplier coupled to an ion counter. The procedure developed was applied to the measurement of nitrate in a certified reference material (stimulated rainwater, CRM 409 from Community Bureau of Reference), in sparkling mineral water, and in tap water. Results were compared with those obtained using ion chromatography. Good agreement (within 1%) was found between the concentration determined by isotope dilution mass spectrometry, the values from ion chromatography, and the certified value. The procedure developed allowed accurate and traceable determinations of nitrate in water samples, with an expanded uncertainty (coverage factor k = 2) of 2-5%, and the detection limit was found to be 2 mumol kg-1.

Apoplastic pH in corn root gravitropism: a laser scanning confocal microscopy measurement

The ability to measure the pH of the apoplast in situ is of special interest as a test of the cell wall acidification theory. Optical sectioning of living seedlings of corn roots using the laser scanning confocal microscope (LSCM) permits us to make pH measurements in living tissue. The pH of the apoplast of corn roots was measured by this method after infiltration with Cl-NERF, a pH-sensitive dye, along with Texas Red Dextran 3000, a pH-insensitive dye, as an internal standard. In the elongation zone of corn roots, the mean apoplastic pH was 4.9. Upon gravitropic stimulation, the pH on the convex side of actively bending roots was 4.5. The lowering of the apoplastic pH by 0.4 units appears to be sufficient to account for the increased growth on that side. This technique provides site-specific evidence for the acid growth theory of cell elongation. The LSCM permits measurements of the pH of living tissues, and has a sensitivity of approximately 0.2 pH units.

Pharmacology and neurochemistry of nefazodone, a novel antidepressant drug

Nefazodone is a new antidepressant drug with a pharmacologic profile distinct from that of the tricyclic, monoamine oxidase inhibitor, and serotonin selective reuptake inhibitor antidepressants. Nefazodone was initially discovered for its ability to block 5-HT2A receptors and its reduced potency as an alpha 1-adrenergic blocker. It was later shown to inhibit both serotonin and norepinephrine uptake in vitro, attributes which most likely impart its clinical efficacy and which differentiate nefazodone from its chemical predecessor trazodone. The combination of these two mechanisms may ultimately result in a facilitation of 5-HT1A-mediated neurotransmission, which may be beneficial for treating symptoms of depression as evidenced by recent clinical findings. In addition, the preclinical profile of nefazodone demonstrates that it has decreased anticholinergic and antihistaminic activity relative to traditional agents. Clinical findings to date are consistent with these observations.

BMY 14802, a sigma receptor ligand for the treatment of schizophrenia

The theoretical role of sigma receptors in psychosis has led to the development of selective sigma receptor ligands as potential antipsychotic agents. BMY 14802 has its most potent binding at the sigma binding site, with some degree of serotonin subtype 1A and negligible dopamine receptor binding. It is atypical of standard neuroleptics in that it does not induce catalepsy in rats. It has been shown to have efficacy in animal models of psychosis. It was hypothesized that the drug would have antipsychotic effects in humans without producing the extrapyramidal side effects typical of standard neuroleptics. We report here the results of an uncontrolled, multicenter safety and efficacy study of patients with acute exacerbations of schizophrenia treated with BMY 14802. After 1 week of single-blind placebo treatment, 28 patients were treated with BMY 14802 (up to 3000 mg/day) for up to 4 weeks. There was no significant improvement in psychiatric symptoms, as measured by the total Brief Psychiatric Rating Scale scores or Clinical Global Improvement. There were no changes in involuntary movements, as measured by the Abnormal Involuntary Movement Scale, or in extrapyramidal symptoms as measured by the Simpson-Angus Scale.

Soluble forms of the human T cell receptor CD4 are efficiently expressed by Streptomyces lividans

We have developed a new gene expression and secretion system for Streptomyces lividans and used it to produce soluble forms of a human T-cell receptor CD4 at levels greater than 300 mg/l. The system uses the transcription, translation and secretion signals of the serine protease inhibitor gene STI-II which is naturally produced by S. longisporus. Using these signals, soluble derivatives of CD4 were secreted directly into the culture supernatant as correctly processed soluble, biologically active proteins. High level expression of the CD4 proteins depended on the transcription initiation signal, the amino acid sequence surrounding the signal peptide cleavage site and temporally controlled protease activities. We discuss these results in the context of the potential of this system for producing other eukaryotic proteins in Streptomyces.

Synthesis and PET studies of fluorine-18-BMY 14802: a potential antipsychotic drug

BMY 14802 is a compound containing fluorine developed as a potential antipsychotic drug. It has a moderate affinity for the sigma binding site and a very low affinity for dopamine D2 receptors and has been predicted to have antipsychotic properties without the side effect potential of existing drugs. To assess the brain uptake, pharmacokinetics, stereoselectivity and binding properties of this potential antipsychotic drug, enantiomerically pure samples of (-) and (+)-[18F]BMY 14802 were examined in a baboon with PET. A tissue distribution with racemic labeled BMY 14802 was also carried out in mice. Radiochemical yields of 15% at the end of bombardment (EOB) for the racemic mixture, and 5% for each enantiomer with a specific activity of 2-5 Ci/mumol at EOB were obtained. In baboons, [18F]BMY 14802 cleared rapidly from the plasma and the glucuronidated [18F]BMY 14802 appeared. Radioactivity peaked (0.04-0.07% dose/cc) in all areas of the brain examined at about 5 min postinjection. It then rapidly cleared to about 30% of peak value by 20 min postinjection and to less than 10% of peak by 60 min postinjection in all regions. A similar rapid clearance from brain was also observed in mice. Pretreatment with unlabeled BMY 14802 (7 mg/kg), did not produce the expected reductions in distribution volume and clearance halftimes consistent with receptor binding. Although the rapid kinetics of [18F]BMY 14802 made it difficult to resolve the processes of transport and binding of the labeled drug, the lack of regional distribution consistent with the known distribution of sigma binding sites as well as the lack of stereoselectivity suggest that the behavior of BMY 14802 in the brain is dominated by its transport properties in tissue rather than its binding to sigma sites. Moreover, its rapid clearance from brain may be a limiting factor in its use as an antipsychotic drug.

Two novel Streptomyces protein protease inhibitors. Purification, activity, cloning, and expression

In contrast to the Gram-negative bacteria, Gram-positive bacteria such as Streptomyces lack a mucopolysaccharide cell wall which allows them to produce and secrete a variety of proteins directly into their environment. In an effort to understand and eventually exploit the synthesis and secretion of proteins by Streptomyces, we identified and characterized two naturally occurring abundantly produced proteins in culture supernatants of Streptomyces lividans and Streptomyces longisporus. We purified these 10-kDa proteins and obtained partial amino acid sequence information which was then used to design oligonucleotide probes in order to clone their genes. Analysis of the sequence data indicated that these proteins were related to each other and to several other previously characterized Streptomyces protein protease inhibitors. We demonstrate that both proteins are protein protease inhibitors with specificity for trypsin-like enzymes. The presumptive signal peptidase cleavage sites and subsequent aminopeptidase products of each protein are characterized. Finally, we show that the cloned genes contain all of the information necessary to direct synthesis and secretion of the proteins by Streptomyces spp. or Escherichia coli.

Buspirone and related compounds as alternative anxiolytics

The desire of the pharmaceutical industry to obtain more selective agents for the treatment of anxiety with fewer or diminished side effects and a profile consistent with safety during long-term use resulted in a search which has identified the azapirones as a new class of anxiolytics which lack structural or biochemical homology with the benzodiazepines. This presentation reviews the efficacy of buspirone (BuSpar), the first of this class to reach wide acceptance, and its analogs, gepirone, ipsapirone, and tandospirone, in the clinical treatment of anxiety and compares their 'anxioselective' profiles to those of the benzodiazepines. The azapirones appear to act as serotonin 5-HT1A partial agonists as they all share high affinity for 5-HT1A binding sites in vitro as well as in anatomical studies. Moreover, their biochemical, electro-physiological, and behavioural actions are consistent with this suggestion. That the serotonergic actions of the azapirones are relevant to their anxiolytic efficacy is suggested by their efficacy in animal models sensitive to other effective anxiolytics as well as their loss of efficacy in such testing following lesions of serotonergic neurons. Thus action upon serotonergic neurotransmission may produce a highly desirable anxioselective profile of effects.

Unique modulation of central 5-HT2 receptor binding sites and 5-HT2 receptor-mediated behavior by continuous gepirone treatment

The effect of continuous treatment with the selective 5-HT1A agonist gepirone upon 5-HT2-mediated behavior and cortical 5-HT2 receptor binding sites was examined in naive rats or rats receiving noradrenergic (DSP4) or serotonergic (5,7-DHT) lesions. Continuous administration of gepirone in non-lesioned rats for 3, 7, or 14 days enhanced the head shake response to the 5-HT agonist quipazine. This enhancement of 5-HT2-mediated behavior occurred despite concomitant down-regulation of cortical 5-HT2 binding sites. However, 28 days of gepirone administration significantly reduced behavioral responsiveness to quipazine. The gepirone-induced facilitation of 5-HT2-mediated behavior observed after 7 days of continuous treatment was blocked in both DSP4 and 5,7-DHT-lesioned rats. However, both noradrenergic and serotonergic denervation failed to modify the down-regulation of 5-HT2 receptor binding sites produced by continuous gepirone administration. These results suggest that the curious dissociation of behavioral and biochemical indices of 5-HT2 receptor function produced by continuous gepirone treatment may be the result of a dual yet separate action of the drug on central presynaptic noradrenergic and serotonergic mechanisms and postsynaptic 5-HT receptors. Furthermore, the postsynaptic action of gepirone which reduces the maximal number of cortical 5-HT2 receptor binding sites may be the result of gepirone's agonist action at postsynaptic 5-HT1A receptors.

Serotonin agents in anxiety

The side effects and unwanted or unnecessary ancillary pharmacological properties of benzodiazepine anxiolytic drugs resulted in a continuing search for new agents with improved profiles of activity. Buspirone was the first novel drug to emerge from this search in almost thirty years. Investigations into its mechanism of action revealed a key role for serotonin in the pharmacotherapy of anxiety. A variety of serotonergic agents are now in preclinical and clinical development as anxiolytics, including 5-HT1A partial agonists, 5-HT2 antagonists, and 5-HT3 antagonists. In addition to the new drugs which will be developed as a consequence of these investigations, their clinical efficacy will prompt the development of new animal models of psychopathology, leading us ever closer to a full understanding of the neurobiological substrates of anxiety. In addition, deployment of these new agents in the armamentaria of the clinician and the basic scientist will lead to new insights into the treatment of other disorders and the biochemical mechanisms by which the effects of these drugs are obtained.

Cloning and expression of cDNA for a human low-Km, rolipram-sensitive cyclic AMP phosphodiesterase

We have isolated cDNA clones representing cyclic AMP (cAMP)-specific phosphodiesterases (PDEases) from a human monocyte cDNA library. One cDNA clone (hPDE-1) defines a large open reading frame of ca. 2.1 kilobases, predicting a 686-amino-acid, ca. 77-kilodalton protein which contains significant homology to both rat brain and Drosophila cAMP PDEases, especially within an internal conserved domain of ca. 270 residues. Amino acid sequence divergence exists at the NH2 terminus and also within a 40- to 100-residue domain near the COOH-terminal end. hPDE-1 hybridizes to a major 4.8-kilobase mRNA transcript from both human monocytes and placenta. The coding region of hPDE-1 was engineered for expression in COS-1 cells, resulting in the overproduction of cAMP PDEase activity. The hPDE-1 recombinant gene product was identified as a low-Km cAMP phosphodiesterase on the basis of several biochemical properties including selective inhibition by the antidepressant drug rolipram. Known inhibitors of other PDEases (cGMP-specific PDEase, cGMP-inhibited PDEase) had little or no effect on the hPDE-1 recombinant gene product. Human genomic Southern blot analysis suggests that this enzyme is likely to be encoded by a single gene. The presence of the enzyme in monocytes may be important for cell function in inflammation. Rolipram sensitivity, coupled with homology to the Drosophila cAMP PDEase, which is required for learning and memory in flies, suggests an additional function for this enzyme in neurobiochemistry.

H1 antihistamines interact with central sigma receptors

Several antihistamines were evaluated for their ability to interact with sigma, muscarinic and histaminic H1 binding sites in rat brain preparations. All of the antihistamines were able to interact with the sigma site, as well as the other two sites. In addition, tripelennamine was found to elicit sigma-like behaviors when administered to rats. This affinity for the sigma site suggests that the compounds may elicit some of their undesirable CNS side effects via this interaction.

Radioreceptor assay of dopamine binding activity in human serum after tiospirone administration

Tiospirone has demonstrated preclinical activities that predict utility as an antipsychotic drug which lacks the potential to produce extrapyramidal side effects. Indeed, human safety trials after single and multiple dose administration did not reveal the presence of any neurological effects. Serum samples from these studies were obtained for radioreceptor assay to determine the level of dopamine binding activity present. After a single 75 mg dose of tiospirone, demonstrable levels of dopamine binding activity were present. A variety of time points were sampled during the multiple dose study wherein subjects received 60 mg, t.i.d. for 28 days. A comparison of levels of dopamine binding activity present in serum samples taken immediately prior to dosing on various days during the course of the study suggested that steady-state was achieved within seven days with repeated administration. No further rises were seen in the remainder of the study, suggesting that further accumulation of the drug did not occur. Furthermore, hourly monitoring on the last day of drug administration did not reveal any difference, relative to the first dose, in peak levels, time to peak level appearance, or rate of disappearance of dopamine binding activity. This suggests that active metabolites do not accumulate nor is there induction of drug metabolism. Plasma levels of tiospirone were also obtained by high-performance liquid chromatography assay at similar time points. With repeated drug administration plasma tiospirone concentrations also achieved a steady state. Statistically significant increases in plasma half-life and area under the time-concentration curve were observed between day 1 and 28.(ABSTRACT TRUNCATED AT 250 WORDS)

Buspirone, a new approach to the treatment of anxiety

Anxiety has historically been treated by agents with a sedative component to their action. In the last decade or so it has been determined that gamma-aminobutyric acid (GABA) receptors may mediate the anxiolytic actions of the benzodiazepines, propanediol carbamates, barbiturates, and ethanol. However, inasmuch as these drugs have additional pharmacological properties (sedation, muscle relaxation, seizure control), the search for an anxioselective drug was continued. Buspirone appears to be such a drug. Clinical studies have clearly demonstrated the efficacy of buspirone in the treatment of generalized anxiety disorder without the ancillary pharmacology of earlier anxiolytics. Buspirone does not act on the GABA receptor. Rather, its most salient interaction with neurotransmitter receptors occurs at the 5-HT1A serotonin receptor. This action is supported by studies focused on receptor binding, anatomical localization, biochemistry, neurophysiology, and animal behavior. The recognition that action at 5-HT1A receptors may be a viable approach to the pharmacotherapy of anxiety is evidenced by the number of other agents of this class under development by a number of pharmaceutical companies.

Atypical antipsychotic agents: patterns of activity in a series of 3-substituted 2-pyridinyl-1-piperazine derivatives

A series of 3-substituted 2-pyridinyl-1-piperazine derivatives have been appended to cyclic imide groups and evaluated for their potential antipsychotic activity. The dopamine receptor affinities of these target molecules, as well as their ability to block apomorphine-induced stereotypy or reverse neuroleptic-induced catalepsy, was dependent on the lipophilic and electronic characteristics of the substituent situated on the pyridine ring. Groups with + omega and - phi values were most consistent with the desired biological profile of the target molecules, the cyano moiety being the optimum choice. Evaluation of compound 12 in a monkey model of amphetamine psychosis, and the regional selectivity it expresses for the A10 dopaminergic cell bodies in electrophysiological experiments, suggest this compound would be an atypical antipsychotic agent with few side effects.

Bone grafts in craniofacial surgery

Bone grafting or bone replacement is an integral part of craniofacial surgery. Most craniofacial surgeons prefer the use of autogenous bone; however, there are exceptions to this, because some plastic surgeons prefer the use of alloplastic implants for replacement of parts or missing segments in the craniomaxillofacial skeleton. Inlay bone grafts are useful in osteotomies because they show little resorption. Onlay bone grafts contour and balance the face aesthetically and enable the surgeon to obtain refinement and fine-tuning in all types of craniofacial reconstruction. These grafts demonstrate more resorption than inlay grafts. However, the use of onlay grafts coupled with soft-tissue shifts of galea and muscle enable the craniofacial surgeon to achieve superior results over those of surgeons primarily concerned with jaw- or tooth-related movements that do not utilize primary bone grafting as a method of augmentation. Superior results today are obtained with various methods and techniques of bone grafting, some of which have been described in this article.

Buspirone analogues. 2. Structure-activity relationships of aromatic imide derivatives

Several analogues of the novel anxiolytic buspirone were synthesized and evaluated in vivo for tranquilizing activity and their ability to reverse neuroleptic-induced catalepsy. The in vitro binding affinities of these compounds were also examined for both the alpha 1 and dopamine D2 receptor systems. The general structure-activity relationships of this series highlight compounds 17, 21, and 32 as having anticonflict activity. Each of these structures contains the 1-(2-pyrimidinyl)piperazine moiety linked by a tetramethylene chain to a variable cyclic imide moiety. Compound 32 (4,4-dimethyl-1-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-2,6- piperidinedione) was found to be equipotent with buspirone in its anxiolytic activity and was therefore selected for extensive preclinical characterization. The pharmacology of buspirone and 32 is contrasted, and the potent serotonin agonist properties of 32 are discussed with reference to its potential contribution to the anxioselective mechanism of this compound.

Three-dimensional CAT scan reconstruction--pediatric patients

Pediatric craniofacial deformities are highly complex disorders. The development of high-speed computers and related software has recently permitted three-dimensional graphics reconstruction of these deformities based on CT and NMR scan data. Such three-dimensional reconstructions are highly useful in the diagnosis, preoperative planning, and postoperative assessment of these complex deformities.

A cryptic plasmid from Nocardia orientalis NRRL 2452, a vancomycin producer

A plasmid was found in Nocardia orientalis (formerly Streptomyces orientalis). Physical characterization of the plasmid DNA indicates a size of 33.5 kb and a single cleavage site for EcoR I. The presence of plasmid, and variation in its copy member, did not directly affect vancomycin resistance or production levels. The plasmid represents the first to be isolated and characterized from a glycopeptide-producing nocardia.