GNTI-122: an autologous antigen-specific engineered Treg cell therapy for type 1 diabetes

Tregs have the potential to establish long-term immune tolerance in patients recently diagnosed with type 1 diabetes (T1D) by preserving β cell function. Adoptive transfer of autologous thymic Tregs, although safe, exhibited limited efficacy in previous T1D clinical trials, likely reflecting a lack of tissue specificity, limited IL-2 signaling support, and in vivo plasticity of Tregs. Here, we report a cell engineering strategy using bulk CD4+ T cells to generate a Treg cell therapy (GNTI-122) that stably expresses FOXP3, targets the pancreas and draining lymph nodes, and incorporates a chemically inducible signaling complex (CISC). GNTI-122 cells maintained an expression profile consistent with Treg phenotype and function. Activation of CISC using rapamycin mediated concentration-dependent STAT5 phosphorylation and, in concert with T cell receptor engagement, promoted cell proliferation. In response to the cognate antigen, GNTI-122 exhibited direct and bystander suppression of polyclonal, islet-specific effector T cells from patients with T1D. In an adoptive transfer mouse model of T1D, a mouse engineered-Treg analog of GNTI-122 trafficked to the pancreas, decreased the severity of insulitis, and prevented progression to diabetes. Taken together, these findings demonstrate in vitro and in vivo activity and support further development of GNTI-122 as a potential treatment for T1D.

[Application value of image fusion technology in transcatheter aortic valve implantation]

Objective: To analysis the application value of image fusion technology in transcatheter aortic valve implantation (TAVI). Methods: A total of 35 patients underwent trans-femoral TAVI using the first-generation VENUS-A valve in Heart Center of Henan Provincial People's Hospital from January 2020 to May 2021 were analyzed retrospectively. Among them, there were 21 males and 14 females, aged from 64 to 81 years, with a mean (SD) of (71.37±5.66) years. They were divided into conventional group (n=22) and fusion group (n=13), according to whether image fusion technology was used during operation. The preoperative general data, intraoperative data, differences of postoperative renal function and residence time in intensive care unit (ICU) were analyzed and compared between the two groups. The postoperative echocardiography and 12 lead ECG were observed. Results: All 35 patients in this study were with severe aortic stenosis, of which, 10 patients were complicated with moderate to severe regurgitation. Compared with the conventional group, the intraoperative fusion group had fewer angiography times [3.0 (3.0, 4.0) vs 5.0 (5.0, 6.0)], X-ray absorbed dose [342.0 (44.5) mGy vs 388.4 (71.0) mGy], and contrast dosage [(73.5±10.5) ml vs (90.3±10.3) ml], and shorter rapid pacing time [(14.0±1.6) seconds vs (16.5±2.0) seconds] (all P<0.05). There was no significant differences in X-ray irradiation time, operation time, sizing of the pre-dilated balloon, valve implantation depth and other indicators (all P>0.05). There was no significant differences in ICU retention time and postoperative renal function (all P>0.05). Postoperative echocardiography showed that the function of aortic valve was good, with mild perivalvular leakage in 2 cases in the conventional group and 1 case in the fusion group; and one patient was implanted with permanent pacemaker after TAVI in the conventional group. Conclusion: Image fusion technology simplifies the TAVI process, shortens the ventricular pacing time and reduces the dosage of X-ray and contrast, and has certain clinical application value.

[Association of glutamate receptor metabotropic 5 polymorphisms with schizophrenia susceptibility in a Chinese Han population]

Objectives: To investigate the association of single nucleotide polymorphisms (SNP) of glutamate receptor metabotropic 5 (GRM5) gene with schizophrenia susceptibility(SZ) in a Chinese Han population. Methods: Twenty-two SNPs located in GRM5 gene in 528 paranoid SZ patients and 528 control subjects recruited from northern Henanwere analyzed. The clinical features of 267 first-episode SZ patients were assessed with the Positive and Negative Syndrome Scale (PANSS). Results: The SZ group included 264 males and 264 females, aged (27±8) years; the healthy control group had 264 males and 264 females, aged (28±8) years.The differences in the genotypic and allelic frequencies of two SNPs (rs567990 and rs12421343) were statistically significant between the SZ patients and control groups (all P<0.05). The allele frequency of rs504183 was also statistically different between the two groups (P=0.030). When the subjects were stratified by sex, the genotypic and allelic frequencies of rs12421343 in female subjects were statistically different between the SZ patients and control groups. The allele frequencies of SNPs (rs12422021, rs567990, and rs7101540) were also statisticallydifferent between the two groups (all P<0.05). Meanwhile, rs567990 AG+GG carriers had a higher risk for SZ than AA carriers in female subjects(OR=1.946, 95%CI: 1.264-2.995). In addition, the patients with different genotypes (GG, AA+AG) of rs12422021 showed statistically significant differences in PANSS total score(84.8±24.4 vs 75.3±18.6), positive (16.2±4.3 vs 14.4±4.2), excitement (12.4±5.1 vs 10.2±4.1) and cognitive impairment factor scores (15.2±6.8 vs 13.3±3.9) (all P<0.05). The patients with AC and the other two genotypes (AA and CC) of rs504183 showed statistically significant differences in PANSS negative factor score(27.4±9.9 vs 24.7±8.4 and 23.4±8.1, both P<0.05). Conclusion: The current study provides further evidence that GRM5 is associated with SZ, and suggests a putative sex difference.

Engineered red blood cells as an off-the-shelf allogeneic anti-tumor therapeutic

Checkpoint inhibitors and T-cell therapies have highlighted the critical role of T cells in anti-cancer immunity. However, limitations associated with these treatments drive the need for alternative approaches. Here, we engineer red blood cells into artificial antigen-presenting cells (aAPCs) presenting a peptide bound to the major histocompatibility complex I, the costimulatory ligand 4-1BBL, and interleukin (IL)-12. This leads to robust, antigen-specific T-cell expansion, memory formation, additional immune activation, tumor control, and antigen spreading in tumor models in vivo. The presence of 4-1BBL and IL-12 induces minimal toxicities due to restriction to the vasculature and spleen. The allogeneic aAPC, RTX-321, comprised of human leukocyte antigen-A*02:01 presenting the human papilloma virus (HPV) peptide HPV16 E7_11-19, 4-1BBL, and IL-12 on the surface, activates HPV-specific T cells and promotes effector function in vitro. Thus, RTX-321 is a potential 'off-the-shelf' in vivo cellular immunotherapy for treating HPV + cancers, including cervical and head/neck cancers.

Abstract PO044: RTX-321, an allogeneic red blood cell-based artificial antigen presenting cell, expressing MHC I-peptide, 4-1BBL and IL-12, engages primary human HPV-specific T cells and boosts other general immune responses

The high-risk human papillomavirus (HPV) strain 16 accounts for ~ 70% of all cervical cancers and 80% of head and neck cancers associated with HPV infection., Despite available therapies, there remains a critical need for new treatment options for advanced HPV 16-associated cancers. To address this, we have genetically engineered red blood cells to create an allogeneic artificial antigen presenting cell (APC), RTX-321, that expresses an HPV E7 peptide bound to MHC I (HLA-A*02:01), 4-1BBL and IL-12 on the cell surface to mimic the biology of T cell APC interactions. RTX-321 is designed to enhance both the quantity and quality of endogenous tumor-specific T cells. In this study, we evaluated the mechanisms through which RTX-321 promotes anti-tumor immune responses, particularly its ability to engage and activate HPV 16-specific CD8+ T cells in the context of mixed immune populations in peripheral blood mononuclear cells (PBMCs) and to modulate other key immune cell types in PBMCs. Primary CD8+ T cells were engineered to express the HPV E7 TCR, resulting in HPV E7-specific CD8+ T cells (E7 TCR-T). To determine whether RTX-321’s immune modulatory activities are dependent on the presence of antigen-specific T cells, we examined the effect of RTX-321 on PMBCs admixed with E7 TCR-T as compared to PBMCs alone. RTX-321 selectively expanded HPV E7-specific CD8+ T cells from the PBMC mixture in a dose-dependent manner. RTX-321 preferentially upregulated activation markers and effector molecules, and promoted effector memory on HPV E7-specific CD8+ T cells, compared to HPV independent CD8+ T cells. In addition to these HPV antigen-specific responses, modulations on other immune cells were observed with RTX-321 treatment. RTX-321 induced activation marker upregulation on general CD8+ T cells, as well as NK cell expansion, activation and effector molecule upregulation, independent of the presence of E7 TCR-T. In PBMCs, RTX-321 increased proinflammatory cytokine and chemokine secretion, including IFNγ, TNFα and CXCL10. The addition of E7 TCR-T cells further increased the production of IFNγ and TNFα in PBMCs, suggesting its potential role in further promoting the immune response by secreting effector molecules. Overall, our data indicate that RTX-321 not only engages HPV 16 antigen-specific CD8+ T cells, but also other key immune cell populations of the adaptive and innate immune systems to promote a broad and robust anti-tumor response. An Investigational New Drug application for RTX-321 for the treatment of patients with HPV 16-positive solid tumors is planned by the end of 2020.

Citation Format: Mengyao Luo, Shamael S. Dastagir, Xuqing Zhang, Andrea Schmidt, Beatriz Marques, Timothy J. Lyford, Billy Blanco, Laurence A. Turka, Thomas J. Wickham, Tiffany F. Chen. RTX-321, an allogeneic red blood cell-based artificial antigen presenting cell, expressing MHC I-peptide, 4-1BBL and IL-12, engages primary human HPV-specific T cells and boosts other general immune responses [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO044.

Abstract B062: Enabling the rapid generation of allogeneic artificial antigen presenting cell (aAPC) Red Cell Therapeutics with a loadable MHC system

Next generation sequencing technologies, coupled with personal neoantigen identification approaches, have significantly improved the capability to develop patient-specific T-cell-based therapies targeting tumors. Current peptide neoantigen vaccine approaches are promising, but do not adequately stimulate and expand patient T cells to the levels required to achieve robust efficacy. To address these limitations, Rubius Therapeutics has developed allogeneic artificial antigen presenting cells (aAPCs), which express the required signals for complete T cell activation: antigenic peptide-MHC complex, costimulatory ligand and cytokine. By engineering red cells to express immunomodulatory signals 1, 2 and 3, these aAPCs dramatically expand antigen-specific T cells in vivo and promote T cell memory and effector function. To use the aAPC approach with personal neoantigens, Rubius Therapeutics has developed a loadable MHC system that enables the rapid generation of aAPCs. Unloaded MHC class I molecules typically do not express robustly on the cell surface, as innate biophysical instability and internal cellular quality control mechanisms prevent MHC molecules that lack a loaded peptide from displaying on the cell surface. We demonstrate here that the empty MHC class I complex can be stably presented on the red cell surface. This was achieved by fusing wild-type MHC class I [human] HLA-A2 and β2 microglobulin to the glycophorin A transmembrane domain. Of note, disulfide engineering of HLA-A2 did not change expression when compared to wild-type constructs on the red cells. Fluorescently labelled peptides were used to measure the kinetics of peptide loading, which demonstrated that disulfide-engineering dramatically increased binding rates. Further, peptide competition experiments indicated slightly increased affinity for peptide with disulfide engineered HLA-A2. Functional testing revealed that addition of exogenous HPV E7 peptide and co-incubation of loaded cells with Jurkat-Lucia NFAT cells expressing HPV E7-specific TCR cells demonstrated TCR-specific activity. Additional TCR activity assays showed that peptide loaded onto empty wild-type HLA-A2 was stable up to 3 days, while disulfide-engineered HLA-A2 activity was abrogated after 1 day. Finally, this concept was extended to other HLA genes, demonstrating that our approach could achieve expression of a variety of HLA alleles on the red cell surface, including MHC class II alleles in the HLA-DR and HLA-DP gene families. Collectively, these results demonstrate that Rubius’ loadable aAPC system is highly generalizable and can be applied to produce aAPC populations presenting multiple antigenic peptides across a range of functional alleles on the red cell surface. Rubius’ allogeneic aAPC system represents a novel approach to generate effective personal neoantigen-specific therapies in a wide patient population with requisite ease of manufacturability

Citation Format: Christopher L Moore, Sneha Pawar, Mellissa Nixon, Timothy J Lyford, Douglas C McLaughlin, Shamael R Dastagir, Abigail Bracha, Lori Melancon, Christopher L Carpenter, Thomas J Wickham, Tiffany F Chen. Enabling the rapid generation of allogeneic artificial antigen presenting cell (aAPC) Red Cell Therapeutics with a loadable MHC system [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B062. doi:10.1158/1535-7163.TARG-19-B062

Genetic Structure Analysis of Y-Chromosome STR and SNP in Population of Wujiang Area, Suzhou City

Abstract

Objective To analyze the genetic phenotypes of Y-chromosome STR and SNP in Han male population of Wujiang area, Suzhou City and explore the genetic structure of population of Wujiang area for further examination of regional-specific Y-SNP genetic markers ancestor haplogroups. Methods Blood samples of 472 Wujiang area Han males were randomly collected and genotyped by Yfiler^TM Plus PCR Amplification Kit. The allele frequencies and haplotype frequencies of each locus were obtained using the direct calculation method. Y-SNP haplogroups of each sample were estimated using Y-Predictor software and verified through experiments by amplification refractory mutation system-polymerase chain reaction （ARMS-PCR）. Results A total of 453 haplotypes were found in the 27 Y-STR genetic markers in 472 Han males of Wujiang area. The haplotype diversity （HD） was 0.997 696 93, among which, the highest gene diversity （GD） value was DYF387S1a/b （GD=0.953 1） and the lowest was DYS438 （GD=0.321 8）. Based on genotyping data of 27 Y-STRs and 472 samples, 132 haplogroups from C, D, N, O and Q, etc downstream Y-SNP haplogroups were estimated and then verified through experiments. Conclusion This study is based on Y-chromosome STR haplotypes, and predicts Y-SNP haplogroups by Y-Predictor software, then uses ARMS-PCR to verify. Y-SNP genetic markers were introduced to achieve precise analysis of the genetic structure of male families in population of three towns in Wujiang area.

Abstract 3260: Engineered red-cell therapeutics (RCT) as artificial antigen presenting cells promotein vivoexpansion and anti-tumor activity of antigen specific T cells

T cell-based therapies have demonstrated efficacy in a small subset of cancers; however, they have the potential to proliferate uncontrollably and manufacturing these therapies at scale has proven difficult. To address this limitation, Rubius Therapeutics has genetically engineered red cells to create allogeneic artificial antigen presenting cells (RCT-aAPCs) that express MHC class I loaded with a tumor specific antigen, together with costimulatory molecules that recapitulate normal APC-T cell interactions. These RCT-aAPC cells are designed to expand and activate tumor-specific T cells already present within the patient, thus eliminating the need to individually manufacture patient-derived T cells. As a proof of principle, red cells were engineered to express mouse MHC class I H-2Kb loaded with OVA 257-264 peptide and murine 4-1BBL. These cells induced in vitroT cell proliferation of OVA antigen-specific OT1 cells, whereas red cells expressing only MHC I or 4-1BBL did not induce proliferation. The RCT-aAPC expanded OT1 cells demonstrated an activated phenotype with increased CD44 expression, secretion of both IFNγ and IL2, as well as antigen-specific tumor killing of EG7.OVA tumor cells. To test in vivo efficacy, a mouse surrogate RCT-aAPC was created using murine red blood cells chemically conjugated with H-2Kb OVA and the m4-1BBL molecule. CellTrace Violet (CTV)-labeled OT1 cells were adoptively transferred into B6 Cd45.1 mice followed by intravenous dosing of the RCT-aAPC several hours later. Significant OT1 proliferation was observed 3-4 days post-dosing as measured by CTV dilution. Administration of a second RCT-aAPC dose at this time drove &gt;200-fold expansion of OT1 cells with a memory-like phenotype in the peripheral blood and secondary lymphoid organs. Using a similar dosing strategy, administration of RCT-aAPC to mice bearing EG7.OVA tumors caused 60% tumor growth inhibition by Day 7 after dosing, which corresponded with the increased expansion of the OT1s. Treatment with RCT-aAPC significantly prolonged survival compared to the control group (p-val = 0.0024). After interacting with RCT-aAPC, antigen-specific T cells, traffic to the lymph nodes and tumor as demonstrated by OT1 presence at these sites. Based on the proof of concept using a murine system, human RCT-aAPCs expressing [human] 4-1BBL and [human] HLA-A2 loaded with an HPV E7 peptide were developed to expand and activate HPV E7-specific T cells. These RCT-aAPC cells activated TCR signaling in primary HPV E7-specific T cells as measured by upregulation of Nur77 expression and in engineered HPV E7-specific TCR Jurkat lines, measured using an NFAT luciferase reporter assay. Further validation of RCT-aAPC is ongoing and will be the focus for future clinical development in patients with HPV-positive cancers.

Citation Format: Xuqing Zhang, Shamael R. Dastagir, Naren Subbiah, Mengyao Luo, Vikram Soman, Sneha Pawar, Douglas C. McLaughlin, Nicholas Bayhi, Viral Amin, Torben Straight Nissen, Christopher L. Carpenter, Thomas J. Wickham, Tiffany F. Chen. Engineered red-cell therapeutics (RCT) as artificial antigen presenting cells promotein vivoexpansion and anti-tumor activity of antigen specific T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3260.

Artificial Anti-Tumor Opsonizing Proteins with Fibronectin Scaffolds Engineered for Specificity to Each of the Murine FcγR Types

We have engineered a panel of novel Fn3 scaffold-based proteins that bind with high specificity and affinity to each of the individual mouse Fcγ receptors (mFcγR). These binders were expressed as fusions to anti-tumor antigen single-chain antibodies and mouse serum albumin, creating opsonizing agents that invoke only a single mFcγR response rather than the broader activity of natural Fc isotypes, as well as all previously reported Fc mutants. This panel isolated the capability of each of the four mFcγRs to contribute to macrophage phagocytosis of opsonized tumor cells and in vivo tumor growth control with these monospecific opsonizing fusion proteins. All activating receptors (mFcγRI, mFcγRIII, and mFcγRIV) were capable of driving specific tumor cell phagocytosis to an equivalent extent, while mFcγRII, the inhibitory receptor, did not drive phagocytosis. Monospecific opsonizing fusion proteins that bound mFcγRI alone controlled tumor growth to an extent similar to the most active IgG2a murine isotype. As expected, binding to the inhibitory mFcγRII did not delay tumor growth, but unexpectedly, mFcγRIII also failed to control tumor growth. mFcγRIV exhibited detectable but lesser tumor-growth control leading to less overall survival compared to mFcγRI. Interestingly, in vivo macrophage depletion demonstrates their importance in tumor control with mFcγRIV engagement, but not with mFcγRI. This panel of monospecific mFcγR-binding proteins provides a toolkit for isolating the functional effects of each mFcγR in the context of an intact immune system.

How patients' use of social media impacts their interactions with healthcare professionals

INTRODUCTION

Patients are increasingly accessing online health information and have become more participatory in their engagement with the advent of social media (SM). This study explored how patients' use of SM impacted their interactions with healthcare professionals (HCPs).

METHODS

Focus groups (n=5) were conducted with 36 patients with chronic conditions and on medication who used SM for health-related purposes. The discussions lasted 60-90min, were audio-recorded, transcribed verbatim, and thematically analysed.

RESULTS

Participants did not interact with HCPs on SM and were not expecting to do so as they used SM exclusively for peer interactions. Most reported improvement in the patient-HCP relationship due to increased knowledge, better communication, and empowerment. Participants supplemented HCP-provided information with peer interactions on SM, and prepared themselves for consultations. They shared online health information with HCPs, during consultations, to validate it and to actively participate in the decision-making. Although some participants reported HCP support for their online activities, most perceived overt or tacit opposition.

CONCLUSION

Participants perceived that their SM use positively impacted relationships with HCPs. They felt empowered and were more assertive in participating in decision-making.

PRACTICE IMPLICATIONS

HCPs should be aware of patients' activities and expectations, and support them in their online activities.

Engineering Aglycosylated IgG Variants with Wild-Type or Improved Binding Affinity to Human Fc Gamma RIIA and Fc Gamma RIIIAs

The binding of human IgG1 to human Fc gamma receptors (hFcγRs) is highly sensitive to the presence of a single N-linked glycosylation site at asparagine 297 of the Fc, with deglycosylation resulting in a complete loss of hFcγR binding. Previously, we demonstrated that aglycosylated human IgG1 Fc variants can engage the human FcγRII class of the low-affinity hFcγRs, demonstrating that N-linked glycosylation of the Fc is not a strict requirement for hFcγR engagement. In the present study, we demonstrate that aglycosylated IgG variants can be engineered to productively engage with FcγRIIIA, as well as the human Fc gamma RII subset. We also assess the biophysical properties and serum half-life of the aglycosylated IgG variants to measure stability. Aglycosylated constructs N297D/S298T (DTT)-K326I/A327Y/L328G (IYG) and N297D/S298A-IYG optimally drove tumor cell phagocytosis. A mathematical model of phagocytosis suggests that hFcγRI and hFcγRIIIA dimers were the main drivers of phagocytosis. In vivo tumor control of B16F10 lung metastases further confirmed the variant DTT-IYG to be the best at restoring wild-type-like properties in prevention of lung metastases. While deuterium incorporation was similar across most of the protein, several peptides within the CH2 domain of DTT-IYG showed differential deuterium uptake in the peptide region of the FG loop as compared to the aglycosylated N297Q. Thus, in this study, we have found an aglycosylated variant that may effectively substitute for wild-type Fc. These aglycosylated variants have the potential to allow therapeutic antibodies to be produced in virtually any expression system and still maintain effector function.

Relationships Between Pharmacovigilance, Molecular, Structural, and Pathway Data: Revealing Mechanisms for Immune-Mediated Drug-Induced Liver Injury

Immune-mediated drug-induced liver injury (IMDILI) can be devastating, irreversible, and fatal in the absence of successful transplantation surgery. We present a novel approach that combines the methods of pharmacoepidemiology with in silico molecular modeling to identify specific features in toxic ligands that are associated with clinical features of IMDILI. Specifically, from pharmacovigilance data multivariate logistic regression identified 18 drugs associated with IMDILI (P < 0.00015). Eleven of these drugs, along with their known and proposed metabolites, constituted a training set used to develop a four-point pharmacophore model (sensitivity 75%; specificity 85%). Subsequently, this information was combined with information from immune-pathway reviews and genetic-association studies and complemented with ligand-protein docking simulations to support a hypothesis implicating two putative targets within separate, possibly interacting, immune-system pathways: the major histocompatibility complex within the adaptive immune system and Toll-like receptors (TLRs), in particular TLR-7, which represent pattern recognition receptors of the innate immune system.

Protein Engineering and Selection Using Yeast Surface Display

Yeast surface display is a powerful technology for engineering a broad range of protein scaffolds. This protocol describes the process for de novo isolation of protein binders from large combinatorial libraries displayed on yeast by using magnetic bead separation followed by flow cytometry-based selection. The biophysical properties of isolated single clones are subsequently characterized, and desired properties are further enhanced through successive rounds of mutagenesis and flow cytometry selections, resulting in protein binders with increased stability, affinity, and specificity for target proteins of interest.

A retrospective study of psychotropic drug use among individuals with mental illness issued a community treatment order

BACKGROUND

Community treatment orders (CTOs) are legal orders which require individuals with mental illness to accept treatment in the community. Previous studies report that long-acting injectable (LAI) antipsychotics are associated with CTOs, however, little is known about the specific treatment plans prescribed in CTOs. The objective of this study was to describe the patterns of psychotropic drugs prescribed to individuals issued a CTO, focusing on LAI antipsychotics, antipsychotic polypharmacy and high-dose antipsychotics.

METHODS

This was a retrospective cross-sectional study of 378 individuals randomly selected from a sample of 1317 individuals with a CTO expiry date up to and including 30 April 2010, taken from all 2856 individuals issued a CTO by the New South Wales Mental Health Review Tribunal, Australia, in 2009. De-identified information relating to individuals' treatment plans, demographic and clinical details were systematically extracted.

RESULTS

A total of 377 (99.7%) individuals were prescribed at least one antipsychotic. Of these, 310 (82%) were prescribed a LAI antipsychotic, either alone (45%), or in combination with, an oral antipsychotic (37%). Risperidone was the most prevalent antipsychotic, prescribed to 164 (43%) individuals. Antipsychotic polypharmacy was prescribed to 121 (32%) individuals and between 20% and 27% of individuals were prescribed high-dose antipsychotics. Antipsychotic polypharmacy accounted for 74-80% of individuals prescribed high-dose antipsychotics.

CONCLUSIONS

The results from this study confirm that LAI antipsychotics are commonly prescribed in CTOs. Antipsychotic polypharmacy was also common, and accounted for the majority of individuals prescribed high-dose antipsychotics. Further research is needed to determine the potential outcomes and implications of the patterns observed.

Abstract 1250: Fibronectin domains engineered for specificity to individual murine Fc gamma receptors modulate tumoricidal activity of immune cells

Activating and inhibitory Fc gamma receptors (FcγRs) can play a large role in the efficacy of certain antibody therapeutics. The Fc regions of the antibody bind to the FcγRs expressed on immune cells and modulate responses against antibody-coated tumor cells. Previous studies with FcγR knock-out mice have shown that antibody-mediated tumor clearance is improved when activating FcγRs are bound preferentially over inhibitory FcγRs. The ectodomains of FcγRs are highly homologous, making it challenging to engineer Fc regions to specifically bind individual FcγRs with high affinity and lack binding to the other FcγRs. To address this challenge, we engineered the human tenth type III fibronectin (Fn3) domain scaffold to bind individual murine FcγRs at epitopes that are distinct from the Fc binding region for testing in a mouse model. The most established pre-clinical models of cancer are mouse models; therefore studying the effect of modulating individual murine FcγRs should provide insight into engaging specific FcγRs as an anti-cancer therapeutic for humans.

Using directed evolution with yeast surface display, we isolated Fn3 clones specific for murine FcγRI, FcγRII, FcγRIII, and FcγRIV through a combination of depletion, enrichment, and mutagenesis steps. Cell titrations measured with flow cytometry confirmed the binding specificity of the Fn3s. Binding epitopes were determined by fluorescence activated cell sorting of a single-point mutant yeast library of FcγR and competition studies. To confirm the biological activity of the Fn3 clones, a tumor-targeting single-chain variable fragment (scFv) was fused to each Fn3 clone. Each scFv-Fn3 construct was antigen specific and bound specifically to the FcγR that it was designed to target. The murine colon carcinoma cell line MC38 stably transfected with carcinoembryonic antigen (CEA) was used for our studies. Tumor cells were pre-incubated with scFv-Fn3 constructs targeting CEA and then combined with thioglycollate- induced peritoneal macrophages pre-treated with interferon gamma. The phagocytic activity of the macrophages was measured using flow cytometry. Pre-incubation with scFv-Fn3 constructs specific for FcγRI or FcγRIV significantly increased phagocytosis compared with pre-incubations with the control scFv-Fn3 construct. Pre-incubation with a combination of both the FcγRI- and FcγRIV-specific constructs resulted in a phagocytosis level close to that of murine IgG2a, which can interact with all of the FcγRs. These Fn3 tools will allow us to conduct future studies on the immune response that is generated by triggering individual FcγRs in other in vitro assays and in vivo models of cancer.

This work was supported by a Sanofi Aventis Biomedical Innovation Award and the NIH/NIGMS Biotechnology Training Program.

Citation Format: Tiffany F. Chen, Kevin Li, K. Dane Wittrup. Fibronectin domains engineered for specificity to individual murine Fc gamma receptors modulate tumoricidal activity of immune cells. [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 1250. doi:10.1158/1538-7445.AM2013-1250

Engineering new protein-protein interactions on the β-propeller fold by yeast cell surface display

REINVENTING THE WHEEL: The β-propeller domain folds like a wheel to provide key protein-protein interactions in the cell. Here we used high-throughput yeast sorting to "invent" β-propellers of new binding specificities with cellular targets.

Triepitopic antibody fusions inhibit cetuximab-resistant BRAF and KRAS mutant tumors via EGFR signal repression

Dysregulation of epidermal growth factor receptor (EGFR) is a hallmark of many epithelial cancers, rendering this receptor an attractive target for cancer therapy. Much effort has been focused on the development of EGFR-directed antibody-based therapeutics, culminating in the clinical approval of the drugs cetuximab and panitumumab. Unfortunately, the clinical efficacy of these drugs has been disappointingly low, and a particular challenge to targeting EGFR with antibody therapeutics has been resistance, resulting from mutations in the downstream raf and ras effector proteins. Recent work demonstrating antibody cocktail-induced synergistic downregulation of EGFR motivated our design of cetuximab-based antibody-fibronectin domain fusion proteins that exploit downregulation-based EGFR inhibition by simultaneously targeting multiple receptor epitopes. We establish that, among our engineered multiepitopic formats, trans-triepitopic antibody fusions demonstrate optimal efficacy, inducing rapid EGFR clustering and internalization and consequently ablating downstream signaling. The combined effects of EGFR downregulation, ligand competition, and immune effector function conspire to inhibit tumor growth in xenograft models of cetuximab-resistant BRAF and KRAS mutant cancers. Our designed triepitopic constructs have the potential to enhance the efficacy and expand the scope of EGFR-directed therapies, and our multiepitopic may be readily applied to other receptor targets to formulate a new class of antibody-based therapeutics.

Effectiveness of interventions to improve antidepressant medication adherence: a systematic review

Non-adherence to antidepressant medications is a significant barrier to the successful treatment of depression in clinical practice. This review aims to systematically assess the effectiveness of interventions for improving antidepressant medication adherence among patients with unipolar depression, and to evaluate the effect of these interventions on depression clinical outcomes. MEDLINE, PsycINFO and EMBASE databases were searched for English-language randomised controlled trials published between January 1990 and December 2010 on interventions to improve antidepressant adherence. The impact of interventions on antidepressant medication adherence (compliance and persistence) and depression clinical outcomes was evaluated. Data concerning the quality of the included studies were also extracted. Twenty-six studies met the inclusion criteria. Interventions were classified as educational, behavioural and multifaceted interventions. A total of 28 interventions were tested, as two studies investigated two interventions each. Sixteen (57%) of the 28 interventions showed significant effects on antidepressant adherence outcomes, whereas 12 (43%) interventions demonstrated significant effects on both antidepressant adherence and depression outcomes. The interventions which showed significant improvement in outcomes were primarily multifaceted and complex, with proactive care management and involvement of mental health specialists. The most commonly used elements of multifaceted interventions included patient educational strategies, telephone follow-up to monitor patients' progress, as well as providing medication support and feedback to primary care providers. Overall, educational interventions alone were ineffective in improving antidepressant medication adherence. In conclusion, improving adherence to antidepressants requires a complex behavioural change and there is some evidence to support behavioural and multifaceted interventions as the most effective in improving antidepressant medication adherence and depression outcomes. More carefully designed and well-conducted studies are needed to clarify the effect of interventions in different patient populations and treatment settings.

Determinants of mental health stigma among pharmacy students in Australia, Belgium, Estonia, Finland, India and Latvia

BACKGROUND

Healthcare professionals commonly exhibit negative attitudes toward people with mental disorders. Few international studies have sought to investigate the determinants of stigma.

OBJECTIVE

To conduct an international comparison of pharmacy students' stigma towards people with schizophrenia, and to determine whether stigma is consistently associated with stereotypical attributes of people with schizophrenia.

METHOD

Students (n = 649) at eight universities in Australia, Belgium, India, Finland, Estonia and Latvia completed a seven-item Social Distance Scale (SDS) and six items related to stereotypical attributes of people with schizophrenia.

RESULTS

Mean SDS scores were 19.65 (+/- 3.97) in Australia, 19.61 (+/- 2.92) in Belgium, 18.75 (+/- 3.57) in India, 18.05 (+/- 3.12) in Finland, and 20.90 (+/- 4.04) in Estonia and Latvia. Unpredictability was most strongly associated with having a high social distance in Australia (beta = -1.285), the perception that people will never recover in India (beta = - 0.881), dangerousness in Finland (beta = -1.473) and the perception of being difficult to talk to in Estonia and Latvia (beta = -2.076). Unpredictability was associated with lower social distance in Belgium (beta = 0.839).

CONCLUSION

The extent to which students held stigmatizing attitudes was similar in each country, however, the determinants of stigma were different. Pharmacy education may need to be tailored to address the determinants of stigma in each country.

Role of dimerization in the catalytic properties of the Escherichia coli disulfide isomerase DsbC

The bacterial protein-disulfide isomerase DsbC is a homodimeric V-shaped enzyme that consists of a dimerization domain, two alpha-helical linkers, and two opposing thioredoxin fold catalytic domains. The functional significance of the two catalytic domains of DsbC is not well understood yet. We have engineered heterodimer-like DsbC derivatives covalently linked via (Gly(3)-Ser) flexible linkers. We either inactivated one of the catalytic sites (CGYC), or entirely removed one of the catalytic domains while maintaining the putative binding area intact. Variants having a single active catalytic site display significant levels of isomerase activity. Furthermore, mDsbC[H45D]-dim[D53H], a DsbC variant lacking an entire catalytic domain but with an intact dimerization domain, also showed isomerase activity, albeit at lower levels. In addition, the absence of the catalytic domain allowed this protein to catalyze in vivo oxidation. Our results reveal that two catalytic domains in DsbC are not essential for disulfide bond isomerization and that a determining feature in isomerization is the availability of a substrate binding domain.

DNA haplotype analysis of CAG repeat in Taiwanese Huntington's disease patients

We studied the expanded CAG repeat and adjacent CCG repeat in 53 Huntington's disease (HD) patients and 172 unrelated normal subjects matched to the patients for ethnic origin. The range of the CAG repeat varied from 38 to 109 in the HD patients and from 10 to 29 in the control group. A significant negative correlation was found between the age at onset and the CAG expansion, with no significant influence of the adjacent CCG repeat on the age at onset by multiple regression analysis. Allelic association using CCG repeat and 2 flanking dinucleotide repeat markers within 150 kb of the HD gene revealed linkage disequilibrium for 2 of 3 markers. Haplotype analysis of 24 HD families using these markers identified 3 major haplotypes underlying 87.5% of HD chromosomes. The data suggested frequent haplotypes in the Taiwanese population on which one or more mutational events leading to the disease occurred.

Inhibitory mechanisms of kinetin, a plant growth-promoting hormone, in platelet aggregation

Kinetin has been shown to have anti-aging effects on several different systems including plants and human cells. The aim of this study was to examine the detailed inhibitory mechanisms of kinetin in platelet aggregation. In this study, kinetin concentration-dependently (50-150 microM) inhibited platelet aggregation in human platelets stimulated by agonists. Kinetin (70 and 150 microM) also concentration-dependently inhibited intracellular Ca2+ mobilization and phosphoinositide breakdown in platelets stimulated by collagen (1 microg/ml). Kinetin (70 and 150 microM) significantly inhibited thromboxane A2 formation stimulated by collagen (1 microg/ml) and arachidonic acid (60 microM) in human platelets. In addition, kinetin (70 and 150 microM) significantly increased the formation of cyclic AMP. Intracellular pH values were measured spectrofluorometrically using the fluorescent probe BCECF-AM in platelets. The thrombin-evoked increase in pHi was markedly inhibited in the presence of kinetin (70 and 150 microM). Rapid phosphorylation of a platelet protein of molecular weight (Mr) 47000 (P47), a marker of protein kinase C activation, was triggered by collagen (1 microg/ml). This phosphorylation was inhibited by kinetin (70 and 150 microM). In conclusion, these results indicate that the anti-platelet activity of kinetin may be involved in the following pathways: kinetin's effects may initially be due to inhibition of the activation of phospholipase C and the Na+/H+ exchanger. This leads to lower intracellular Ca2+ mobilization, followed by inhibition of TxA2 formation and then increased cyclic AMP formation, followed by a further inhibition of the Na+/H+ exchanger, ultimately resulting in markedly decreased intracellular Ca2+ mobilization and phosphorylation of P47. These results suggest that kinetin has an effective anti-platelet effect and that it may be a potential therapeutic agent for arterial thrombosis.

Involvement of nuclear factor-kappaB in lipoteichoic acid-induced cyclooxygenase-2 expression in RAW 264.7 macrophages

We have investigated the role of protein kinase C (PKC) and nuclear factor-kappaB (NF-kappaB) in cyclooxygenase-2 (COX-2) expression caused by Staphylococcus aureus lipoteichoic acid in RAW 264.7 macrophages. A phosphatidylcholine-phospholipase C (PC-PLC) inhibitor (D-609) and a phosphatidylinositol-phospholipase C (PI-PLC) inhibitor (U-73122) attenuated lipoteichoic acid-induced COX-2 expression, while a phosphatidate phosphohydrolase inhibitor (propranolol) had no effect. Two PKC inhibitors (Go 6976 and Ro 31-8220) and the NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC), also attenuated lipoteichoic acid-induced COX-2 expression. Lipoteichoic acid resulted in a decrease in PKC activity in the cytosol and an increase in PKC activity in membranes. The lipoteichoic acid-induced translocation of p65 NF-kappaB from the cytosol to the nucleus was inhibited by D-609, U-73122, Go 6976, Ro 31-8220, and PDTC, but not by propranolol. The results suggested that lipoteichoic acid might have activated PC-PLC and PI-PLC to induce PKC activation, which in turn initiated NF-kappaB activation, and finally induced COX-2 expression in RAW 264.7 macrophages.

Solid-state trans-cis isomerization of captopril determined by thermal Fourier transform infrared (FT-IR) microspectroscopy

Thermal Fourier transform infrared (FT-IR) microspectroscopy was used to investigate the conformational isomerization of captopril in the solid state. The result indicates that the IR peak intensity of captopril for original bands decreased dramatically at 102 degrees C, but for new bands it increased with the rise of temperature. The frequency of C=O stretching mode for carboxylic acid and for amide was located at a higher wavenumber of 1747 cm(-1) and at a lower frequency of 1591 cm(-1) as compared with the general compound, suggesting the existence of trans isomer of captopril in the solid state by intramolecular hydrogen bonding. Beyond 102 degrees C, several new bands at 1720, 1645, and 1610 cm(-1) were observed with the rise of temperature, indicating the coexistence of a cis isomer. However, the cis isomer could transform gradually to the trans isomer after cooling. The thermodynamics of equilibrium mixture of cis/trans isomers were also studied. The trans isomer was more stable than the cis isomer, but the cis isomer was favored at the higher temperature.

N-methylated 5-alkenyloxazolium salt transformations

[reaction: see text] In the course of natural product synthetic studies, 5-(4-pentenyl)oxazole and 5-(5-hexenyl)oxazole were N-methylated. The initial N-methylated 5-alkenyloxazolium salt adducts were found to be only intermediates and were ultimately transformed into hydroindole and hydroisoquinoline compounds, respectively.

Reaction kinetics of solid-state cyclization of enalapril maleate investigated by isothermal FT-IR microscopic system

To investigate the reaction kinetics of the solid-state degradation process of enalapril maleate, a Fourier transform infrared microspectroscope equipped with thermal analyzer (thermal FT-IR microscopic system) was used. The isothermal stability study was conducted at 120-130 degrees C for 1-2 h and changes in the three-dimensional plots of the IR spectra of enalapril maleate with respect to heating time were observed. The study indicates that the bands at 1649, 1728, and 1751 cm(-1) assigned to intact enalapril maleate gradually reduced in peak intensity with heating time. However, the peak intensities at 1672 and 1738 cm(-1) (due to enalapril diketopiperazine (DKP) formation) and at 3250 cm(-1) (corresponding to water formation) gradually increased with heating time. The solid-state diketopiperazine formation and the degradation process of enalapril maleate via intramolecular cyclization were found to be simultaneous. The isothermal decomposition curves were sigmoidal and were characterized by induction and acceleration periods, indicating the presence of autocatalytic solid-state decompositions. Moreover, the power-law equation (n = 1/4) was found to provide the best fit to the kinetics of decomposition. This isothermal FT-IR microscopic system was easily used to investigate the degradation of enalapril maleate and the concomitant formation of DKP. The solid-state reaction of enalapril maleate required an activation energy of 195+/-12 kJ/mol to undergo the processes of decomposition and intramolecular cyclization.

Thermal-Dependent dehydration process and intramolecular cyclization of lisinopril dihydrate in the solid state

The pathway of dehydration and intramolecular cyclization of lisinopril dihydrate in the solid state was investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and a combination of thermal analyzer with Fourier transform infrared microspectroscopy (thermal FT-IR microscopic system). The results indicate that the dehydration from the solid-state lisinopril dihydrate had a two-step process from dihydrate to monohydrate at 76 degrees C and then from monohydrate to anhydrate at 99-101 approximately C, which could be clearly observed from the above three methods. Only the thermal FT-IR microscopic system could give vital information on diketopiperazine (DKP) formation via intramolecular cyclization in anhydrous lisinopril. A new peak at 1670 cm(-1) assigned to the carbonyl band of DKP formation was clearly evidenced. The water of reaction byproduct was liberated at a temperature >157 degrees C and appeared on the IR spectra near 3200-3400 cm(-1). Moreover, the peak at 1574 cm(-1) assigned to carboxylate shifted to 1552 cm(-1) due to the DKP formation. The peak at 1670 cm(-1) related to the DKP formation changed slightly in intensity from 147 degrees C and significantly near 157 degrees C. DSC and TGA methods were poor for use in supplying information on DKP formation in lisinopril. The thermal FT-IR microscopic system is useful from the view point that it can quickly and directly show the solid-state stability of drug.

[Treatment of nasofacial hemangioma with interventional embolization and pingyungmycin injection]

OBJECTIVE

To investigate a new method with interventional embolization and pingyugmycin injection for treating nasofacial Hemangioma.

METHOD

The fillets and coil were used for interventional embolization facial artery, internal maxillary artery, temporal superficial artery, and pingyungmycin injected for 4 patients.

RESULT

The tumor and vascular beat in this series of 4 patients were disappeared by follow up of one year. There are not nasal obstruction and epistaxis.

CONCLUSION

Treatment with interventional embolization and pingyungmycin injection is a safe and effective method for nasofacial hemangioma.

Clinical, electrophysiological characteristics, and radiofrequency catheter ablation of atrial tachycardia near the apex of Koch's triangle

Atrial tachycardia, with its focus near the apex of Koch's triangle, may carry a potential risk of atrioventricular block during radiofrequency catheter ablation. The efficacy and safety of this procedure have never been addressed. The characteristics and catheter ablation results are reported for six patients with atrial tachycardia near the apex of Koch's triangle. All six patients were female aged 49.6 +/- 9.3 years (range 39-63). Organic heart disease was present in 3 (50%) of the 6 patients. The P wave in surface ECG had a mean axis of -28 degrees (range -90 degrees - +30 degrees) in the frontal plane. The catheter ablation was guided by activation sequence mapping. The energy was titrated from low power level. Atrial overdrive pacing was used to monitor the atrioventricular conduction should accelerated junctional rhythm occur. At the final successful ablation site, the local atrial activation was 41.8 +/- 9.1 ms before the P wave and His-bundle potential was present in 5 of the 6 patients. All patients had their atrial tachycardia eliminated without recurrence or heart block during a follow-up period of 17.7 +/- 8.5 months (range 6-30). In conclusion, atrial tachycardia near the apex of Koch's triangle has distinct clinical and electrophysiological features. Radiofrequency catheter ablation can be performed effectively. However, extreme care must be taken to prevent inadvertent atrioventricular block. Titrated energy application and continuous monitoring of atrioventricular conduction are mandatory.

Mechanism of cooling-induced relaxation in the isolated guinea-pig trachea

In this study, we explored the possible mechanism of cooling-induced relaxation of the isolated guinea-pig trachea. A rapid cooling (-4 degrees C/min) from 37 +/- 0.5 degree C to 25 +/- 0.5 degree C induced a transient and small contraction followed by a sustained cooling-relaxation. This relaxation was not blocked by propranolol or tetrodotoxin. Various concentrations of four contractile agonists (histamine, carbachol, 5-HT and ryanodine) all enhanced cooling-relaxation in a concentration-dependent manner which correlated well with their increase in the developed muscular tension, suggesting an inherent counterbalance between cooling-relaxation and the bronchoconstriction. Treating with either indomethacin or nordihydroguaiaretic acid (NDGA) did not affect the contractile properties of histamine, carbachol and 5-HT except ryanodine, but reversed cooling-relaxation into sustained cooling-contraction. Indomethacin partially inhibited but NDGA abolished cooling-relaxation induced by ryanodine. Moreover, ryanodine, but not the other three contractile agonists, could antagonize indomethacin in inducing cooling-contractions by various agonists. From above findings, we can conclude that eicosanoids including prostaglandins particularly leukotrienes, which would be produced by the elevated Ca(2+)-release from the ryanodine sensitive Ca(2+)-store, play prominent roles in inducing cooling-relaxation.

Aetiopathogenesis and management of impotence in diabetic males: four years experience from a combined clinic

The contribution of organic and psychogenic factors in the aetiopathogenesis of impotence was studied in a large number of diabetic males, to develop an algorithm for its management. We examined 110 consecutive patients who were referred to the Impotence Clinic of the Diabetes Centre. All patients were initially evaluated by a diabetologist and then underwent psychosexual assessment by a specialized psychiatrist. Patients with primarily organic disease were referred to a urologist for further management while those with psychogenic impotence received psychosexual counselling. Peripheral neuropathy was present in 71 (65%) and two or more autonomic tests were abnormal in 22 (20%) patients. Neuropathy was the only cause detected in 29 (27%) patients, the main cause in 22 (20%), and contributing, but not the main factor, in 20 (18%). Psychogenic factors were the only cause detected in 12 (11%) patients, the main cause in 26 (24%) and contributed in 19 (17%). Marital disharmony, medical treatment, and peripheral vascular disease were the main aetiopathogenic factors in the remaining cases. Psychosexual counselling resulted in successful intercourse in 17 (60%) out of the 24 treated patients and papaverine injections in 31 (61%) out of 56 treated patients. It is concluded that although organic factors are mainly responsible for the development of impotence in diabetic males, psychological factors contribute significantly and psychosexual assessment and counselling are essential adjuncts to its management. Treatment with papaverine injections is generally inexpensive and effective to overcome the multifactorial causes of erectile dysfunction in this population. An algorithm which may facilitate the investigation and treatment of impotent diabetic males is proposed.

Intermuscular bupivacaine infusion for control of pain after renal surgery: a preliminary report

OBJECTIVE

To assess the value of continuous bupivacaine wound infusion for post-operative pain relief after renal surgery.

PATIENTS AND METHODS

The analgesic efficacy of continuous intermuscular wound infusion with 0.25% bupivacaine was studied in 10 patients (four men, six women), with a mean age of 47.5 years (range 25-71) and a mean weight of 71.2 kg (range 44-99), after renal surgery in a single-blind randomized trial. The results were compared with those of an age- and weight-matched control group of 10 patients (five men, five women) with a mean age of 47.7 years (range 27-73) and a mean weight of 67.3 kg (range 51-85). Post-operative pain was studied objectively by assessing individual patient's morphine requirements administered via a patient controlled analgesia system, and subjectively with pain scores. Patient mobility was assessed by ward nursing staff using mobility score charts.

RESULTS

There was a lower demand for post-operative analgesia in the bupivacaine group compared with the control. Although there was no significant difference in the pain scores between the two groups, the bupivacaine group was significantly more mobile than the control group after surgery. There was no significant difference in the mean post-operative hospital stay between the two groups.

CONCLUSION

Continuous intermuscular bupivacaine wound infusion is a simple and safe procedure which lowers the patients' post-operative analgesic requirements, allows for earlier mobility and may promote more rapid discharge from hospital.

A district urinary catheter policy. Why have one?

A catheter audit was performed at the Central Manchester Trust, which found that there was excessive ordering, inappropriate catheter selection by size, materials, balloon size and poor guidelines on catheter storage. From these findings and from the available literature, we have proposed guidelines on catheter selection with the aim of offering the best patient care and to provide cost efficiency which may be of benefit to other hospitals.

Inhibition in the human urinary bladder by gamma-amino-butyric acid

OBJECTIVE

To investigate the effects of gamma-amino-butyric acid (GABA) on detrusor activity in man to determine whether it has any inhibitory effect on detrusor contraction. The inhibitory neurotransmitter GABA has been found in mammalian urinary bladders and the effects of GABA on detrusor activity in the rabbit bladder has previously been described [1].

MATERIALS AND METHODS

Human detrusor muscle strips, obtained at cystectomy, were made to contract by electrical stimulation of their autonomic nerves or by the addition of carbachol in a superfusion apparatus. GABA and its analogues were added to the superfusion chamber and any changes in the responses were measured.

RESULTS

The electrically evoked nerve-mediated contractions in human bladder muscle were exclusively cholinergic. GABA inhibited nerve-mediated contractions in human detrusor muscle-strips by the activation of the GABAB receptor, since baclofen (a GABAB receptor agonist) produced similar inhibition and muscimol (a GABAA receptor agonist) did not. There was no inhibition of carbachol-mediated contractions by GABA.

CONCLUSION

This in vitro study shows that GABA has a peripherally mediated inhibitory effect on excitatory neurotransmission in human detrusor muscle. The site of action is on the post-ganglionic nerves and appears to be mediated via the GABAB receptor.

Rectal obstruction secondary to carcinoma of the prostate treated by transanal resection of the prostate

Rectal obstruction caused by carcinoma of the prostate is uncommon. If the disease does not respond to either hormonal treatment or radiotherapy, the only surgical means of relieving the obstruction has been the formation of a colostomy. We present an alternative treatment, since many of these patients are elderly with a short life expectancy and they may have difficulty coping with a stoma. Seven transanal endoscopic resections of the prostate (TARP) have been performed on 5 patients. The procedure is not without complications, but it does offer simple surgical palliation of the rectal obstruction and obviates the need for a colostomy.

Inhibitory role of gamma-amino-butyric acid in the rabbit urinary bladder

Gamma-amino-butyric acid (GABA) is an established inhibitory neurotransmitter in the central nervous system (CNS) and it has also been identified in the bladder. We have investigated in the rabbit the effect of GABA on detrusor activity. Rabbit detrusor muscle strips were made to contract by electrical stimulation of their autonomic nerves or by the addition of carbachol. The addition of GABA caused substantial inhibition of muscle contraction. GABA acts on 2 classes of receptors-GABAA and GABAB. The inhibition was mediated via the GABAB receptors as its effect was mimicked by baclofen (a GABAB agonist) and inhibited by 2-hydroxysaclofen (a GABAB receptor antagonist). Inhibition was not prevented by bicuculline (a GABAA receptor antagonist). This inhibition may be due to a direct muscle effect since the inhibition, which occurred with carbachol-induced contraction, was not abolished by the addition of tetrodotoxin. GABA, acting via the GABAB receptor, produces substantial inhibition of muscle contraction in the rabbit urinary bladder. This raises the possibility of using GABAB analogues in the treatment of detrusor instability.

Epididymectomy for post-vasectomy pain: histological review

Fifteen epididymectomies were performed on 10 patients with post-vasectomy pain and 12 specimens were available for histopathological review. The findings were compared with those in 2 groups in which epididymectomy was performed for chronic epididymo-orchitis and epididymal cysts. The results showed that 50% of the post-vasectomy group were cured by simple epididymectomy. Pathological findings revealed features of long-standing obstruction and interstitial and perineural fibrosis which may have accounted for the pain. It is important to recognise this late complication of vasectomy and, if surgery is to be performed, to include all of the distal vas and previous vasectomy site in the excision.

Intraperitoneal rupture of an infected urachal cyst in an infant. Case report

Peritonitis due to intraperitoneal rupture of an infected urachal cyst is a life-threatening condition, not previously reported in an infant. We report this condition in an 8-month-old infant. The child underwent complete excision of the urachal remnant and made an uneventful recovery; bacterial culture grew Staphylococcus aureus. Subsequent investigations did not reveal any other renal tract abnormalities.

Occult blood loss from small bowel tumours. Case report

We report 4 patients who presented with occult blood loss, from a small bowel adenocarcinoma, in whom there was considerable delay in diagnosis. The difficulty in diagnosis and the role of CT scanning is discussed. We recommend a careful laparotomy when endoscopic and radiological investigations fail to reveal the source of blood loss.

Obstructing tracheal lipoma: management of a rare tumor

Benign neoplasms of the trachea are rare. We describe a 46-year-old patient with a lipoma arising from the membranous trachea and causing severe respiratory obstruction. Investigation and management of this problem are discussed, and the literature is reviewed.

[Enhancement of absorption of tetramethylpyrazine by synthetic borneol]

Sprague-Dawley rats were given ig tetramethylpyrazine phosphate (TMP) 5 mg/kg with or without previous borneol 5 mg/kg. The plasma TMP concentrations were analysed by GC method, and the data were treated by NONLIN program. The Cmax were 931 and 562 ng/ml, respectively, (P less than 0.01); while the AUC were 68,849 and 37,174, respectively, (P less than 0.05). It is suggested that the borneol enhances the absorption of the TMP but not in elimination.

[A case report and metallurgical analysis of broken Luque rod]

Wire breakage is frequently mentioned in Luque rod instrumentation with segmental sublaminar wiring, but breakage of the Luque rod is rare. A case report of a broken Luque rod in a patient following a scoliosis post-corrective operation is presented and a metallurgical analysis is provided to evaluate the mechanism of breakage. In the metallurgical analysis, we find many slots and dimples on the rod surface which were induced by an inappropriate bending apparatus and bending manipulation. These defects resulted in a stress concentration effect and initiated fatigue. As for the stress on the rod, this resulted from the force correcting the scoliotic deformity plus the load resulting from patient's daily activity, which increased the progression of fatigue and then induced the final breakage. So, to avoid Luque rod breakage we suggest that the bending manipulation be done appropriately, with external orthosis given to those patients with severe deformity or who are daily very active.

Mass spectrometry of L-beta-aspartamido carbohydrates isolated from ovalbumin

Using ovalbumin as a starting material, we have isolated and purified relatively large stocks of known glycopeptides for use as models with which to investigate and develop mass spectrometric procedures for the analysis of this class of compounds. In the process, we have discovered six new components in the L-beta-aspartamido carbohydrate fraction of ovalbumin. Positive and negative fast atom bombardment mass spectra, produced on a KRATOS MS50-TC, confirm that the newly found chromatographic peaks correspond to as yet unidentified compounds in the molecular weight range of 1000-3000. Fragment ion peaks present in the mass spectra of some of the unknown compounds can be rationalized in terms of the fragment ion patterns established from the structures of the known glycoasparagines.