Whose public, whose goods? Generations of patients and visions of fairness in Ghanaian health

Since Ghana's independence in 1957, the country has seen an ebb and flow of reforms intended to expand and fund state healthcare, informed by diverse notions of affordability and adequate provision. Cycles of attempted health reforms have emerged from disparate political and economic ideologies, themselves a product of broader global histories and specific national experiences. Based on group interviews with people across most administrative regions of Ghana, this paper examines how the formative historical experiences of different generations gives rise to a multiplicity of understandings of what constitutes a 'fair' distribution of national health resources. It discusses the forms and contents of arguments that people of different ages raised in both rural and urban settings in the course of the study - with particular reference to the operation of Ghana's current National Health Insurance Scheme, and in light of their perceptions of the justice or injustice of present day healthcare in relation to earlier periods.

Wilful Blindness: Sleeping Sickness and Onchocerciasis in Colonial Northern Ghana, 1909-1957

As a contribution to the existing literature on deliberate or unintended neglect, concealment and ignorance regarding significant and enduring public health problems-produced by economic marginality, lack of political power and institutional failures affecting specific places and groups-this article discusses the history of epidemic sleeping sickness and endemic onchocerciasis in colonial northern Ghana from 1909 to 1957. Despite accumulating evidence of their serious impacts on the health of northern communities, and calls to action on the part of some health officials, both diseases were only officially recognised as significant risks when it was no longer politically possible to deny them. The particular histories of each disease, in the same region over the same decades, reveal two comparable and interrelated trajectories of neglect.

The nature and measurement of schizophrenic thought disorder

The work to be reported is a replication and refinement of a previous study (Bannister, 1960). As preface to the previous study, four traditional approaches to the problem of schizophrenic thought disorder were briefly reviewed, namely “dissociation” (Kretschmer 1936), “deterioration in mental efficiency” (Babcock, 1933), “concretism” (Kasanin 1946) and “overinclusion” (Payne, Matussek and George, 1959). These explanations and the experimental work arising from them were not utilized in the current research since it is argued that they suffer from three major defects.

Preclinical Evaluation of MEDI0641, a Pyrrolobenzodiazepine-Conjugated Antibody-Drug Conjugate Targeting 5T4

Antibody-drug conjugates (ADC) are used to selectively deliver cytotoxic agents to tumors and have the potential for increased clinical benefit to cancer patients. 5T4 is an oncofetal antigen overexpressed on the cell surface in many carcinomas on both bulk tumor cells as well as cancer stem cells (CSC), has very limited normal tissue expression, and can internalize when bound by an antibody. An anti-5T4 antibody was identified and optimized for efficient binding and internalization in a target-specific manner, and engineered cysteines were incorporated into the molecule for site-specific conjugation. ADCs targeting 5T4 were constructed by site-specifically conjugating the antibody with payloads that possess different mechanisms of action, either a DNA cross-linking pyrrolobenzodiazepine (PBD) dimer or a microtubule-destabilizing tubulysin, so that each ADC had a drug:antibody ratio of 2. The resulting ADCs demonstrated significant target-dependent activity in vitro and in vivo; however, the ADC conjugated with a PBD payload (5T4-PBD) elicited more durable antitumor responses in vivo than the tubulysin conjugate in xenograft models. Likewise, the 5T4-PBD more potently inhibited the growth of 5T4-positive CSCs in vivo, which likely contributed to its superior antitumor activity. Given that the 5T4-PBD possessed both potent antitumor activity as well as anti-CSC activity, and thus could potentially target bulk tumor cells and CSCs in target-positive indications, it was further evaluated in non-GLP rat toxicology studies that demonstrated excellent in vivo stability with an acceptable safety profile. Taken together, these preclinical data support further development of 5T4-PBD, also known as MEDI0641, against 5T4⁺ cancer indications. Mol Cancer Ther; 16(8); 1576-87. ©2017 AACR.

MHC class I chain-related protein A and B (MICA and MICB) are predominantly expressed intracellularly in tumour and normal tissue

BACKGROUND

Major histocompatibility complex (MHC) class I chain-related protein A (MICA) and MHC class I chain-related protein B (MICB) are polymorphic proteins that are induced upon stress, damage or transformation of cells which act as a 'kill me' signal through the natural-killer group 2, member D receptor expressed on cytotoxic lymphocytes. MICA/B are not thought to be constitutively expressed by healthy normal cells but expression has been reported for most tumour types. However, it is not clear how much of this protein is expressed on the cell surface.

METHODS

Using a novel, well-characterised antibody and both standard and confocal microscopy, we systematically profiled MICA/B expression in multiple human tumour and normal tissue.

RESULTS

High expression of MICA/B was detected in the majority of tumour tissues from multiple indications. Importantly, MICA/B proteins were predominantly localised intracellularly with only occasional evidence of cell membrane localisation. MICA/B expression was also demonstrated in most normal tissue epithelia and predominantly localised intracellularly. Crucially, we did not observe qualitative differences in cell surface expression between tumour and MICA/B expressing normal epithelia.

CONCLUSIONS

This demonstrates for the first time that MICA/B is more broadly expressed in normal tissue and that expression is mainly intracellular with only a small fraction appearing on the cell surface of some epithelia and tumour cells.

Abstract B170: Discovery of tubulysin payloads for antibody drug conjugates with potent in vitro activity and in vivo efficacy in solid tumor models

Antibody drug conjugates (ADCs) combine the specificity of antibodies with the potency of small molecule cytotoxic drugs and have the potential to provide significant efficacy as a treatment for cancer. The objective of this work was to identify potent new cytotoxic ADC payloads that can be used to target diverse tumor types. Here we report for the first time the discovery of fully synthetic tubulysin payloads which belong to a class of highly cytotoxic natural products that disrupt the cellular microtubule network leading to apoptosis of tumor cells. Our fully synthetic tubulysin payloads are comprised of: (i) a tubulysin warhead that displays pM potency, (ii) a protease cleavable amino-acid sequence and (iii) a tether bearing a reactive maleimide group. Tubulysin-based ADCs were generated via site-specific conjugation of these payloads to cysteines engineered into antibodies against cancer antigen target oncofetal protein 5T4. The resulting ADCs showed potent in vitro cell killing and in vivo efficacy in multiple solid tumor xenograft models including prostate cancer, non-small cell lung adenocarcinoma, breast cancer and gastric carcinoma. Furthermore, specific structural features of the tubulysin warhead, linker design and antibody engineering were shown to impact the overall in vitro and in vivo properties of the ADCs. Thus, these synthetic tubulysin payloads represent novel microtubule network disrupting compounds that display potent preclinical anti-tumor activity as an ADC that could be advanced to the clinic.

Citation Format: Dorin Toader, Jay Harper, Chris Lloyd, Rose Marwood, David Bannister, Shenlan Mao, Cui (Tracy) Chen, Haihon (Helen) Zhong, Vahe Bedian, Fengjiang Wang, Lakshmaiah Gingipalli, Melisa Vasbinder, Pamela Thompson, Ryan Fleming, Byniam Bezabeh, Nazzareno Dimasi, Changshou Gao, Adeela Kamal. Discovery of tubulysin payloads for antibody drug conjugates with potent in vitro activity and in vivo efficacy in solid tumor models. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B170.

Identification and Characterization of MEDI4736, an Antagonistic Anti-PD-L1 Monoclonal Antibody

Programmed cell-death 1 ligand 1 (PD-L1) is a member of the B7/CD28 family of proteins that control T-cell activation. Many tumors can upregulate expression of PD-L1, inhibiting antitumor T-cell responses and avoiding immune surveillance and elimination. We have identified and characterized MEDI4736, a human IgG1 monoclonal antibody that binds with high affinity and specificity to PD-L1 and is uniquely engineered to prevent antibody-dependent cell-mediated cytotoxicity. In vitro assays demonstrate that MEDI4736 is a potent antagonist of PD-L1 function, blocking interaction with PD-1 and CD80 to overcome inhibition of primary human T-cell activation. In vivo MEDI4736 significantly inhibits the growth of human tumors in a novel xenograft model containing coimplanted human T cells. This activity is entirely dependent on the presence of transplanted T cells, supporting the immunological mechanism of action for MEDI4736. To further determine the utility of PD-L1 blockade, an anti-mouse PD-L1 antibody was investigated in immunocompetent mice. Here, anti-mouse PD-L1 significantly improved survival of mice implanted with CT26 colorectal cancer cells. The antitumor activity of anti-PD-L1 was enhanced by combination with oxaliplatin, which resulted in increased release of HMGB1 within CT26 tumors. Taken together, our results demonstrate that inhibition of PD-L1 function can have potent antitumor activity when used as monotherapy or in combination in preclinical models, and suggest it may be a promising therapeutic approach for the treatment of cancer. MEDI4736 is currently in several clinical trials both alone and in combination with other agents, including anti-CTLA-4, anti-PD-1, and inhibitors of IDO, MEK, BRAF, and EGFR.

Evaluation of strategies to control Fab light chain dimer during mammalian expression and purification: A universal one-step process for purification of correctly assembled Fab

Fabs are an important class of antibody fragment as both research reagents and therapeutic agents. There are a plethora of methods described for their recombinant expression and purification. However, these do not address the issue of excessive light chain production that forms light chain dimers nor do they describe a universal purification strategy. Light chain dimer impurities and the absence of a universal Fab purification strategy present persistent challenges for biotechnology applications using Fabs, particularly around the need for bespoke purification strategies. This study describes methods to address light chain dimer formation during Fab expression and identifies a novel CH 1 affinity resin as a simple and efficient one-step purification for correctly assembled Fab.

Epitope mapping and key amino acid identification of anti-CD22 immunotoxin CAT-8015 using hybrid β-lactamase display

Monoclonal antibodies are a commercially successful class of drug molecules and there are now a growing number of antibodies coupled to toxic payloads, which demonstrate clinical efficacy. Determining the precise epitope of therapeutic antibodies is beneficial in understanding the structure-activity relationship of the drug, but in many cases is not done due to the structural complexity of, in particular, conformational protein epitopes. Using the immunotoxin CAT-8015 as a test case, this study demonstrates that a new methodology, hybrid β-lactamase display, can be employed to elucidate a complex epitope on CD22. Following insertion of random CD22 gene fragments into a permissive site within β-lactamase, proteins expressed in Escherichia coli were first screened for correct folding by resistance to ampicillin and then selected by phage display for affinity to CAT-8015. The optimal protein region recognised by CAT-8015 could then be used as a tool for fine epitope mapping, using alanine-scanning analysis, demonstrating that this technology is well suited to the rapid characterisation of antibody epitopes.

Parallel, high-throughput purification of recombinant antibodies for in vivo cell assays

We describe a method for high-throughput, parallel purification of secreted proteins to analyse large numbers of protein samples in cell-based assays for the discovery of protein therapeutics. The procedure is generic and capable of 96 parallel purifications and compatible, in both yield and purity, with a wide assay range. By optimising expression and purification steps as well as using novel hardware, in particular a chromatography press capable to purify target proteins from viscous media, we exemplify the process for the generation of single-chain Fv antibody fragments (scFv) and the purification of full-length IgG. The described process can operate robustly with a throughput of over 2,000 samples per month.

Minor burns lead to major changes in synthesis rates of plasma proteins in the liver

The effect of minor burns on the rates of synthesis of plasma proteins in the liver was studied in white Buffalo rats. Burns of second to third degree, covering 0.8% of total body surface, were produced by short application of a hot piece of metal to the skin under ether anesthesia. Levels of mRNA in extracts from liver removed after 24 hr were measured by hybridization to radioactively labeled specific cDNA probes. The level of mRNA for major acute phase alpha 1-protein (also called cysteine proteinase inhibitor or T1-kininogen) increased 20-fold, that of fibrinogen mRNA 8-fold, and that of alpha 1-acid glycoprotein mRNA about 9-fold. The levels of albumin mRNA and transthyretin mRNA (also called prealbumin) decreased to about 80% of normal and the level of transferrin mRNA did not change significantly. Thus, although the percentage of burnt skin was only very small, a typical acute phase response of plasma protein synthesis in liver was observed.

Rat choroid plexus specializes in the synthesis and the secretion of transthyretin (prealbumin). Regulation of transthyretin synthesis in choroid plexus is independent from that in liver

Synthesis of total protein and of transthyretin in rat choroid plexus was studied by measuring the incorporation of radioactive leucine into proteins in choroid plexus tissue incubated in vitro. About 20% of the protein newly synthesized in choroid plexus and about 50% of the newly synthesized protein secreted into the medium was transthyretin. Evidently, the choroid plexus is very active in the biosynthesis of this carrier protein for thyroid hormones and could be an important link in the chemical communication between the body and the central nervous system. Acute inflammation, which leads to a profound rearrangement of the pattern of plasma protein synthesis rates in the liver, produced distinct changes in the levels for plasma protein mRNAs in the liver. The levels of the mRNAs for alpha 1-acid glycoprotein and major acute phase alpha 1-protein increased more than 30-fold, those for transthyretin and albumin decreased to 27 and 57% of normal, respectively. The pattern of the observed changes in the levels of mRNAs for plasma proteins in the liver was independent of whether the acute inflammation was produced by subcutaneous injection of turpentine or intraperitoneal injection of a suspension of talcum. However, levels of transthyretin mRNA in choroid plexus were affected only very slightly, or not at all. Apparently, transthyretin synthesis in liver and choroid plexus is regulated independently during the acute phase response. No mRNA was detected in choroid plexus for albumin, alpha 1-acid glycoprotein, and major acute phase alpha 1-protein under any conditions.

Information about microorganisms contained in patent specifications

Although patents are an important source for information on microorganisms, a survey disclosed that catalogs from culture collection depositories are unreliable in relating the availability with the microorganisms disclosed in a patent.

Reversing the process of thought disorder: a serial validation experiment

Previous personal construct theory studies of thought disorder suggest that it can be viewed as a state of grossly loosened construing (a weak and unstable network of links between ideas) and that it can fairly be measured by grid method. Later studies in the series indicated that it is people not things which bewilder the thought-disordered patient--it is his role as a 'psychologist' that is specifically damaged. The serial invalidation hypothesis argued that thought disorder is the long-term consequence of a repeated failure to predict accurately the behaviour of others and self, resulting in the disintegration of any organized, personal 'theory' about relationships. The present experiment attempt to reverse the process of thought disorder by first identifying whatever weak, remaining system of expectations the thought-disordered patient manifests and then fulfilling these expectations. Such a process of serial validation might lead to a strengthening of the 'theory' which generated these expectations--a tightening of the construct system. Experimental and control group were closely studied over a two-year period. Results-while tending in the predicted direction--yield a not proven verdict though they leave the argument viable and the experiment worth modified replication.

The logical requirements o f research into schizophrenia

Calculations based on Bellak's (1958) review of research into schizophrenia suggest that at that time well over 5,000 papers had been published. An index count of Psychological Abstracts since 1960 indicates that papers on schizophrenia have been produced at the rate of about 300 per year with a growth rate of 10 per cent. per annum. Yet few, viewing the problem of schizophrenia in perspective, feel that any kind of break-through has been made, and many would agree that the field is grossly confused. It may well be that the traditional cry that “more research is needed” misses the point, and that much of the research which has been carried out is of relatively little value because of our failure to meet the logical requirements for effective research within the area.

The diagnosis and treatment of schizophrenia. A questionnaire study of psychiatric opinion

Variations in the attitude of psychiatrists to schizophrenia range from the precise and confident pronouncement of Sargant and Slater (1963) “Chlorpromazine seems to bring the schizophrenic process to a rapid halt, and to lessen the chance of chronicity and deterioration of personality” to the fundamental doubts expressed by Szasz (1957) “The problem of schizophrenia, which many consider to be the core-problem of psychiatry today, may be truly akin to the ‘problem of the ether‘. To put it simply, there is no such problem.” The literature abounds in varying, conflicting and even irreconcilable treatment suggestions. One has only to compare the physical treatment schedules recommended by Sargant (1963) with the advocacy of psychotherapy put forward by Arieti (1959); or the views on drugs of Kalinowski (1958) with the Hordern and Hamilton (1963) assertion that drug results have not been shown to be superior to the effects of “moral treatment” of a century ago. Similar comparisons in the social field might be made between the views of Hamilton and Salmon (1962) and Hamilton (1964) on sheltered workshops and the difficulties of rehabilitation programmes demonstrated by Catterson et al. (1963).

The rationale and clinical relevance of repertory grid technique

All forms of Repertory Grid technique are derivatives of an original proposed by G. A. Kelly (1955) as an integral part of the development of Personal Construct Theory (summarized Bannister, 1962). In essence, repertory grids are forms of sorting test. They differ from conventional sorting tests in that there are no standard sorting materials or sorting categories nor is there any standard single form of administration or scoring procedure. Their unique characteristics are that: