N-acetyl-L-leucine for Niemann-Pick type C: a multinational double-blind randomized placebo-controlled crossover study

BACKGROUND

Niemann-Pick disease type C (NPC) is a rare autosomal recessive neurodegenerative lysosomal disease characterized by multiple symptoms such as progressive cerebellar ataxia and cognitive decline. The modified amino acid N-acetyl-leucine has been associated with positive symptomatic and neuroprotective, disease-modifying effects in various studies, including animal models of NPC, observational clinical case studies, and a multinational, rater-blinded phase IIb clinical trial. Here, we describe the development of a study protocol (Sponsor Code "IB1001-301") for the chronic treatment of symptoms in adult and pediatric patients with NPC.

METHODS

This multinational double-blind randomized placebo-controlled crossover phase III study will enroll patients with a genetically confirmed diagnosis of NPC patients aged 4 years and older across 16 trial sites. Patients are assessed during a baseline period and then randomized (1:1) to one of two treatment sequences: IB1001 followed by placebo or vice versa. Each sequence consists of a 12-week treatment period. The primary efficacy endpoint is based on the Scale for the Assessment and Rating of Ataxia, and secondary outcomes include cerebellar functional rating scales, clinical global impression, and quality of life assessments.

DISCUSSION

Pre-clinical as well as observational and phase IIb clinical trials have previously demonstrated that IB1001 rapidly improved symptoms, functioning, and quality of life for pediatric and adult NPC patients and is safe and well tolerated. In this placebo-controlled cross-over trial, the risk/benefit profile of IB1001 for NPC will be evaluated. It will also give information about the applicability of IB1001 as a therapeutic paradigm for other rare and common neurological disorders.

TRIAL REGISTRATIONS

The trial (IB1001-301) has been registered at www.

CLINICALTRIALS

gov (NCT05163288) and www.clinicaltrialsregister.eu (EudraCT: 2021-005356-10). Registered on 20 December 2021.

Abstract P6-14-08: Epithelial/stromal cross talks that induce malignant transition of human ductal carcinoma in situ

Background: A large fraction of human DCIS (>50%) may not need the multimodality treatment options currently offered to all patients. More importantly, while we may be overtreating many, we cannot identify those most at risk for invasion/metastasis. Revealing the cellular and molecular mechanisms by which some DCIS remain indolent while others advance to invasive and metastatic breast cancers is currently a clinical unmet need. Methods: To address this gap, we developed the Mouse-INtraDuctal (MIND) model, by which patient-derived (PDX) DCIS epithelial cells are injected intraductally and allowed to progress naturally in mice. Single cell RNA-sequencing (scRNA-seq) was utilized to profile the DCIS epithelial and stroma cells in progressors vs. non-progressors. To distinguish between stromal (diploid) cells and tumor (aneuploid) cells, we calculated Copy Number Aberration (CNA) profiles from RNA using CopyKAT. Cell-type specific differential gene expression analysis of DCIS epithelial cells and microenvironment cell types in progressors and non-progressors was performed. We also predicted putative ligand:receptor interactions between the tumor cells and cell types in the microenvironment by CellPhoneDB. Results: Among 37 PDX DCIS MIND models followed for a median of 9 months, 20 (54%) grafted into 95 glands, showed in vivo invasive progression (progressed) while 17 (46%), injected into 107 glands, remained non-invasive (non-progressed). ScRNA-seq was performed on 13 DCIS samples including 10 progressors and 3 non-progressors. Aneuploid cells were further analyzed to identify deferentially expressed genes that were upregulated in progressors compared to non-progressors (log2 fold=1, FDR p< 0.05).. Notable genes included NEAT1, EIF4EBP1, SCGB2A2, TFF1 and TFF3 that were upregulated in the progressors. NEAT1, the core structural component of the paraspeckles, is frequently overexpressed in human cancers and its expression is correlated with worse survival in cancer patients. NEAT1 drives tumor progression by regulating genes involved in cellular growth, migration, invasion, metastasis, EMT, stemness, radio- and chemoresistance, supporting its role as a potential biomarker and therapeutic target. TFF1/TFF3 mRNAs show increased expression in metastatic breast cancers. EIF4EBP1 is located on chrom 8p11-p12 which is frequently amplified in breast cancer and is associated with poor clinical prognosis. Further analysis using Cancer Hallmarks identified mitotic spindle, interferon signaling, DNA repair, oxidative phosphorylation and P53 pathway among the top signatures that were upregulated in the progressors. CellPhoneDB identified expression of several receptor/ligand interactions including CD74/MIF involved in epithelial/stromal and stromal/stromal cross talks that may play a role in DCIS invasive progression. Conclusions: Future studies will validate our findings using patient DCIS samples with known long-term outcome and in vivo MIND models to further refine risk associated biomarkers for invasion/metastasis and to identify more effective treatments.

Citation Format: Aditi Rastogi, Fariba Behbod, Nicholas Navin, Jerome Lin, Linheng Li, Hua Li, Andrew K. Godwin, Alastair M. Thompson, Timothy Fields, Yan Hong. Epithelial/stromal cross talks that induce malignant transition of human ductal carcinoma in situ. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-14-08.

Paraneoplastic Nephropathy with Peculiar Immunofluorescence Pattern: Report of a Rare Case

Introduction/Objective

Hematolymphoid neoplasms are commonly associated with medical renal disease; however, association of renal cell carcinoma and nephrotic/nephritic syndrome is exceedingly rare. Paraneoplastic nephropathy in setting of renal cell carcinoma can manifest as membranous nephropathy, IgA nephropathy, or minimal change disease. The purpose of this report is to describe a rare case of clear cell renal cell carcinoma with associated membranous nephropathy with concurrent glomerular IgG and IgA deposition.

Methods/Case Report

A 68-year-old male presented with a penile mass. Diagnostic work up reveled an 11cm renal mass. Urinalysis demonstrated nephrotic range proteinuria (>5 g/d). Subsequently, the patient underwent nephrectomy and penectomy. Pathologic evaluation showed clear cell renal carcinoma with sarcomatoid component and metastasis to penis. Nonneoplastic kidney workup revealed membranous glomerulopathy, with 3+ granular IgG predominantly within glomerular capillaries and 2+ IgA and 1+ C3 in a similar pattern. Electron microscopy demonstrated numerous subepithelial and intramembranous immune deposits, and few small mesangial deposits. Concurrent membranous and IgA nephropathy has been reported, but the IgA in that case is typically mesangial. The peculiar pattern of IgG and IgA deposition in this case can be seen with membranous nephropathy secondary to lupus or neoplasia. Lupus was excluded based on patient’s history, serology, and absence of significant C1q staining. Therefore, the findings were consistent with membranous glomerulopathy secondary to patient’s cancer. Patient’s proteinuria improved after nephrectomy. He is alive and disease-free 10months after nephrectomy, with proteinuria in 0.1-0.6 g/d range.

Results (if a Case Study enter NA)

NA

Conclusion

This case highlights the importance of thorough evaluation of non-neoplastic kidney in nephrectomy specimens for cancer, thus guiding the type of surgical intervention. Non-orthodox presentation of immunoglobulin deposition may be the herald of neoplasia in select cases.

Abstract LB165: Preclinical evaluation of carnosic acid (CA) and rosemary extract standardized to 40% carnosic acid (RE40CA) for the prevention of invasive breast cancer

Background: There is an unmet need for the development of safer and more effective therapies for the prevention of human invasive breast cancer, for which ductal carcinoma in situ (DCIS) is a precursor. Currently, anti-hormonal therapies are the only option in individuals previously diagnosed with hormone receptor positive breast cancer. However, these agents are associated with many side effects. Furthermore, there are currently no preventive options for hormone receptor negative breast cancers. To study DCIS progression, we developed a model referred to as MIND (Mouse-INtraDuctal) in which patient-derived DCIS cells and cell lines are injected intraductally and studied as they progress to invasive ductal carcinoma (IDC). Previously we provided strong evidence for the role of B Cell Lymphoma-9 (BCL9) as a potential driver of DCIS malignancy. We chose to target BCL9 using RE40CA and its active ingredient CA previously identified in a screen for inhibitors of β-catenin binding to BCL9.

Experimental Strategy: CA and RE40CA were administered to DCIS.COM MIND animal models for four weeks by oral gavage or mixed in a powder diet formulation. Drug plasma levels were evaluated by LC-MS. Four weeks following drug administration, mammary glands were excised and evaluated for efficacy and expression of biomarkers of aggressive DCIS, nuclear β-catenin and BCL9. For efficacy studies, mammary glands containing DCIS like lesions were processed and subjected to immunofluorescence staining using anti-human CK-5, anti-SMA, Dapi, β-catenin and BCL9. Extent of DCIS in vivo growth, number of invasive lesions, tumor number and tumor volume were evaluated for each mammary gland.

Results: Efficacy studies showed a significant reduction in the number of invasive lesions by administration of CA by oral gavage (CA OG:10mg/kg), CA at 200mg/kg diet (CA200), CA400 and RE40CA 500. A significant reduction in extent of DCIS in vivo growth was achieved by CA OG and RE40CA 500. A significant reduction in the number of tumors was achieved by CA OG, RE40CA OG (25mg/kg equivalent to CA 10mg/kg), RE40CA 100, RE40CA 500 and RE40CA 1000. A significant reduction in tumor volume was achieved by CA OG, RE40CA OG, RE40CA 100, RE40CA 500 and RE40CA 1000. Linear regression modelling was used to compare statistical differences among the groups and differences that reached p-value <0.05 were considered significant. Administration of CA or RE40CA by oral gavage was also associated with a significant loss of nuclear BCL9/β-catenin expression in DCIS epithelial cells. Dietary administration of CA and RE40CA as OG or mixed in powder diet showed an increasing trend in plasma concentrations as the dose was increased. Evaluation of HE stained sections of animal organs by histopathology showed no evidence in any tissue of necrosis, degeneration, inflammation or neoplasia. Additionally, no consistent lesions attributable to treatment were observed in any of the animals or groups.

Conclusion: Administration of CA and RE40CA are safe and effective in prevention of DCIS malignancy. Future studies are aimed at testing the efficacy of CA/RE40CA using DCIS cell lines representing other DCIS subtypes (ER+/PR+ and HER2 overexpressing) as well as patient derived DCIS MIND animal models. Supported by NCI PREVENT Cancer Preclinical Drug Development Program, 75N91019D00016/75N91020F00001.

Citation Format: Yan Hong, Aditi Rastogi, Aryamitra Banerjee, Brandon L. Plattner, Matthew Lindeblad, Alexander V. Lyubimov, Timothy Fields, Seema A. Khan, Altaf Mohammed, Jeremy J. Johnson, Fariba Behbod. Preclinical evaluation of carnosic acid (CA) and rosemary extract standardized to 40% carnosic acid (RE40CA) for the prevention of invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB165.

Posttransplant proteinuria due to Apolipoprotein E2 deposition in a kidney allograft

Lipoprotein deposition disorders limited to the kidney and causing proteinuria are rare. We present a case of nephrotic range proteinuria presenting within 4 months after deceased donor renal transplantation in a patient with end-stage kidney disease presumed secondary to hypertension. Two transplant kidney biopsies were performed sixteen weeks after transplantation, and one year after the first biopsy, both showing lipoprotein deposits in the glomeruli, progressive focal segmental glomerulosclerosis, and effacement of visceral foot processes. The patient had a normal lipid profile. Based on previous case reports of Apolipoprotein E variants causing proteinuria in native kidneys, Apolipoprotein E genotyping was performed. Genotyping showed Apolipoprotein E2 homozygosity. This Apolipoprotein E variant has been associated with lipoprotein deposition, proteinuria, and progressive kidney disease in the native kidneys. However, this is the first case of Apolipoprotein E2 homozygosity-related kidney disease in a transplant recipient. The patient was treated with fenofibrate, angiotensin enzyme inhibition, and angiotensin receptor blockade with reduction in proteinuria, and he kept good stable kidney function.

POS0134 INCREASED PREVALENCE OF LUMBAR SPINE MONOSODIUM URATE DEPOSITION AMONG GOUT PATIENTS ON DUAL-ENERGY CT

Background:

Gout affecting the spine is reported as a rare event presenting with neuropathy, spinal compression and acute back pain (1). Cases are often diagnosed by tissue confirmation of monosodium urate (MSU) deposition. The frequency of gout involving the spine asymptomatically or with milder, non-specific symptoms is likely higher than reported.

Objectives:

Using dual-energy CT (DECT), we are determining prevalence/extent of MSU deposition in the lumbosacral spines of patients with gout and tophaceous gout, compared to non-gout controls.

Methods:

We are recruiting 25 controls, 25 non-tophaceous and 25 tophaceous gout patients, 45-80 years old. Exclusion criteria include CPPD disease, RA, spondyloarthropathy or spinal malignancy. All gout subjects meet ACR gout classification criteria with entry serum urate (sU) of >6.8 mg/dL, or sU >6.0 mg/dL on ULT for <6 months. Demographics, gout history, Aberdeen back pain scale, sU, ESR, and CRP are collected. DECT of the lumbosacral spine is used to assess MSU deposition and osteoarthritic changes.

Results:

63 subjects are enrolled and analyzed to date (25 control, 23 non-tophaceous and 15 tophaceous gout). Control, non-tophaceous gout, and tophaceous gout subjects have similar mean age in years (controls 61.8±3.8, non-tophaceous 64.0±6.2, tophaceous 63.5±9.2, p=0.45), but differ in BMI (controls 28.3±6.5 kg/m2, non-tophaceous 32.1±6.7 kg/m2, tophaceous 29.1±4.3 kg/m2, p=0.01) and creatinine (controls 1.0±0.2 mg/dL, non-tophaceous 1.4±0.6 mg/dL, tophaceous 1.7±0.9 mg/dL, p=0.048). Mean sU and ESR are higher in gout subjects (sU-controls 5.3±1 mg/dL, non-tophaceous 8.3±1.4 mg/dL, tophaceous 8.4±2.0 mg/dL, p<0.05; ESR-controls 13.7±13.8 mm/h, non-tophaceous 25.2±18.7 mm/h, tophaceous 22.5±15.1 mm/h, p<0.05). Using default threshold settings for MSU visualization, greater MSU deposition is observed in the spine of gout patients (controls 2.2±1.2 cm3, non-tophaceous 4.5±4.3 cm3, tophaceous 8.5±12.5 cm3, p<0.05; Table 1). Reanalysis of several scans using narrower threshold settings to limit possible artifact confirms increased MSU signal among gout patients. Although many subjects in each group do not have excessive MSU deposition, deposition is more common in both gout groups. No subject demonstrated a frank spinal tophus.

Conclusion:

Based on preliminary results, gout patients have higher inflammatory markers and greater spinal MSU deposition than controls. Preliminary analyes with more stringent DECT threshold settings suggests these differences are not artifact, but analysis is ongoing. These data suggest that MSU deposition in the spine occurs in a subset of gout patients.

References:

[1]Toprover M, Krasnokutsky S, Pillinger MH. Gout in the Spine: Imaging, Diagnosis, and Outcomes. Curr Rheumatol Rep. 2015;17(12):70.

Figure 1.

DECT of the spine. (A) Patient with tophaceous gout (SU 8.9mg/dL, DECT volume 39.76cm3). (B) Control patient (SU 4.5mg/dL, DECT volume 0.70cm3).

Table 1.

Baseline characteristics and mean DECT deposition volumes. Bold font indicates statistical significance.

CharacteristicControlNon-tophaceous GoutTophaceous GoutP-valueNumber of subjects252315Age in years, mean ± SD61.8 ± 3.864.0 ± 6.263.5 ± 9.20.45Male sex, n (%)23 (92.0)23 (100.0)13 (86.7)0.23Race:0.52 -White, n (%)18 (72.0)14 (60.9)7 (46.7) -Black, n (%)6(24.0)6 (26.1)6 (40.0) -Hispanic, n (%)1 (4.0)3 (13.0)2 (13.3)BMI, mean ± SD28.3 ± 6.532.1 ± 6.729.1 ± 4.30.01Chronic kidney disease, n (%)0 (0.0)6 (26.1)3 (20.0)0.03Diabetes mellitus type II, n (%)3 (12.0)5 (21.7)2 (13.3)0.62Hyperlipidemia, n (%)14 (56.0)15 (65.2)7 (46.7)0.52History of myocardial infarction, n (%)1 (4.0)2 (8.7)1 (6.7)0.80Mean sU, mg/dL ± SD5.31 ± 0.988.25 ± 1.48.42 ± 2.0<0.001Mean ESR, mm/hr ± SD (normal 0-10)13.7 ± 13.825.2 ± 18.722.53 ± 15.10.04Mean CRP, mg/L ± SD (normal 0-5)2.7 ± 4.77.6 ± 12.54.1 ± 5.00.13Mean serum creatinine, mg/dL ± SD0.97 ± 0.181.36 ± 0.581.70 ± 0.880.048Mean DECT volume, cm32.2 ± 1.24.5 ± 4.38.5 ± 12.5p<0.05

Acknowledgements:

Supported by an investigator-initiated grant from Horizon Therapeutics

Disclosure of Interests:

Michael Toprover Consultant of: Horizon Pharmaceuticals, Michael Mechlin: None declared, Anastasia Slobodnick: None declared, Virginia C. Pike: None declared, Cheongeun Oh: None declared, Claudine Davis: None declared, Theodore Fields Consultant of: Horizon Pharmaceuticals, Avion Pharmaceuticals, Fabio Becce Consultant of: Horizon Therapeutics, Michael H. Pillinger Consultant of: Horizon Pharmaceuticals, Grant/research support from: Horizon Pharmaceuticals

A master protocol to investigate a novel therapy acetyl-L-leucine for three ultra-rare neurodegenerative diseases: Niemann-Pick type C, the GM2 gangliosidoses, and ataxia telangiectasia

BACKGROUND

The lack of approved treatments for the majority of rare diseases is reflective of the unique challenges of orphan drug development. Novel methodologies, including new functionally relevant endpoints, are needed to render the development process more feasible and appropriate for these rare populations and thereby expedite the approval of promising treatments to address patients' high unmet medical need. Here, we describe the development of an innovative master protocol and primary outcome assessment to investigate the modified amino acid N-acetyl-L-leucine (Sponsor Code: IB1001) in three separate, multinational, phase II trials for three ultra-rare, autosomal-recessive, neurodegenerative disorders: Niemann-Pick disease type C (NPC), GM2 gangliosidoses (Tay-Sachs and Sandhoff disease; "GM2"), and ataxia telangiectasia (A-T).

METHODS/DESIGN

The innovative IB1001 master protocol and novel CI-CS primary endpoints were developed through a close collaboration between the Industry Sponsor, Key Opinion Leaders, representatives of the Patient Communities, and National Regulatory Authorities. As a result, the open-label, rater-blinded study design is considerate of the practical limitations of recruitment and retention of subjects in these ultra-orphan populations. The novel primary endpoint, the Clinical Impression of Change in Severity© (CI-CS), accommodates the heterogenous clinical presentation of NPC, GM2, and A-T: at screening, the principal investigator appoints for each patient a primary anchor test (either the 8-m walk test (8MWT) or 9-hole peg test of the dominant hand (9HPT-D)) based on his/her unique clinical symptoms. The anchor tests are videoed in a standardized manner at each visit to capture all aspects related to the patient's functional performance. The CI-CS assessment is ultimately performed by independent, blinded raters who compare videos of the primary anchor test from three periods: baseline, the end of treatment, and the end of a post-treatment washout. Blinded to the time point of each video, the raters make an objective comparison scored on a 7-point Likert scale of the change in the severity of the patient's neurological signs and symptoms from video A to video B. To investigate both the symptomatic and disease-modifying effects of treatment, N-acetyl-L-leucine is assessed during two treatment sequences: a 6-week parent study and 1-year extension phase.

DISCUSSION

The novel CI-CS assessment, developed through a collaboration of all stakeholders, is advantageous in that it better ensures the primary endpoint is functionally relevant for each patient, is able to capture small but meaningful clinical changes critical to the patients' quality of life (fine-motor skills; gait), and blinds the primary outcome assessment. The results of these three trials will inform whether N-acetyl-L-leucine is an effective treatment for NPC, GM2, and A-T and can also serve as a new therapeutic paradigm for the development of future treatments for other orphan diseases.

TRIAL REGISTRATION

The three trials (IB1001-201 for Niemann-Pick disease type C (NPC), IB1001-202 for GM2 gangliosidoses (Tay-Sachs and Sandhoff), IB1001-203 for ataxia telangiectasia (A-T)) have been registered at www.clinicaltrials.gov (NCT03759639; NCT03759665; NCT03759678), www.clinicaltrialsregister.eu (EudraCT: 2018-004331-71; 2018-004406-25; 2018-004407-39), and https://www.germanctr.de (DR KS-ID: DRKS00016567; DRKS00017539; DRKS00020511).

BCL9/STAT3 regulation of transcriptional enhancer networks promote DCIS progression

The molecular processes by which some human ductal carcinoma in situ (DCIS) lesions advance to the more aggressive form, while others remain indolent, are largely unknown. Experiments utilizing a patient-derived (PDX) DCIS Mouse INtraDuctal (MIND) animal model combined with ChIP-exo and RNA sequencing revealed that the formation of protein complexes between B Cell Lymphoma-9 (BCL9), phosphoserine 727 STAT3 (PS-727-STAT3) and non-STAT3 transcription factors on chromatin enhancers lead to subsequent transcription of key drivers of DCIS malignancy. Downregulation of two such targets, integrin β3 and its associated metalloproteinase, MMP16, resulted in a significant inhibition of DCIS invasive progression. Finally, in vivo targeting of BCL9, using rosemary extract, resulted in significant inhibition of DCIS malignancy in both cell line and PDX DCIS MIND animal models. As such, our studies provide compelling evidence for future testing of rosemary extract as a chemopreventive agent in breast cancer.

Claudin-2 deficiency associates with hypercalciuria in mice and human kidney stone disease

The major risk factor for kidney stone disease is idiopathic hypercalciuria. Recent evidence implicates a role for defective calcium reabsorption in the renal proximal tubule. We hypothesized that claudin-2, a paracellular cation channel protein, mediates proximal tubule calcium reabsorption. We found that claudin-2-null mice have hypercalciuria due to a primary defect in renal tubule calcium transport and papillary nephrocalcinosis that resembles the intratubular plugs in kidney stone formers. Our findings suggest that a proximal tubule defect in calcium reabsorption predisposes to papillary calcification, providing support for the vas washdown hypothesis. Claudin-2-null mice were also found to have increased net intestinal calcium absorption, but reduced paracellular calcium permeability in the colon, suggesting that this was due to reduced intestinal calcium secretion. Common genetic variants in the claudin-2 gene were associated with decreased tissue expression of claudin-2 and increased risk of kidney stones in 2 large population-based studies. Finally, we describe a family in which males with a rare missense variant in claudin-2 have marked hypercalciuria and kidney stone disease. Our findings indicate that claudin-2 is a key regulator of calcium excretion and a potential target for therapies to prevent kidney stones.

Inhibition of Endothelial PHD2 Suppresses Post-Ischemic Kidney Inflammation through Hypoxia-Inducible Factor-1

BACKGROUND

Prolyl-4-hydroxylase domain-containing proteins 1-3 (PHD1 to PHD3) regulate the activity of the hypoxia-inducible factors (HIFs) HIF-1 and HIF-2, transcription factors that are key regulators of hypoxic vascular responses. We previously reported that deficiency of endothelial HIF-2 exacerbated renal ischemia-reperfusion injury, whereas inactivation of endothelial PHD2, the main oxygen sensor, provided renoprotection. Nevertheless, the molecular mechanisms by which endothelial PHD2 dictates AKI outcomes remain undefined.

METHODS

To investigate the function of the endothelial PHD2/HIF axis in ischemic AKI, we examined the effects of endothelial-specific ablation of PHD2 in a mouse model of renal ischemia-reperfusion injury. We also interrogated the contribution of each HIF isoform by concurrent endothelial deletion of both PHD2 and HIF-1 or both PHD2 and HIF-2.

RESULTS

Endothelial deletion of Phd2 preserved kidney function and limited transition to CKD. Mechanistically, we found that endothelial Phd2 ablation protected against renal ischemia-reperfusion injury by suppressing the expression of proinflammatory genes and recruitment of inflammatory cells in a manner that was dependent on HIF-1 but not HIF-2. Persistence of renoprotective responses after acute inducible endothelial-specific loss of Phd2 in adult mice ruled out a requirement for PHD2 signaling in hematopoietic cells. Although Phd2 inhibition was not sufficient to induce detectable HIF activity in the kidney endothelium, in vitro experiments implicated a humoral factor in the anti-inflammatory effects generated by endothelial PHD2/HIF-1 signaling.

CONCLUSIONS

Our findings suggest that activation of endothelial HIF-1 signaling through PHD2 inhibition may offer a novel therapeutic approach against ischemic AKI.

Advancing Risk-Informed Decision Making in Managing Defense Nuclear Waste in the United States: Opportunities and Challenges for Risk Analysis

An omnibus spending bill in 2014 directed the Department of Energy to analyze how effectively Department of Energy (DOE) identifies, programs, and executes its plans to address public health and safety risks that remain as part of DOE's remaining environmental cleanup liabilities. A committee identified two dozen issues and associated recommendations for the DOE, other federal agencies, and the U.S. Congress to consider, as well as other stakeholders such as states and tribal nations. In regard to risk assessment, the committee described a risk review process that uses available data, expert experience, identifies major data gaps, permits input from key stakeholders, and creates an ordered set of risks based on what is known. Probabilistic risk assessments could be a follow-up from these risk reviews. In regard to risk management, the states, in particular, have become major drivers of how resources are driven. States use different laws, different priorities, and challenge DOE's policies in different ways. Land use decisions vary, technology choices are different, and other notable variations are apparent. The cost differences associated with these differences are marked. The net result is that resources do not necessarily go to the most prominent human health and safety risks, as seen from the national level.

Abstract P4-06-01: Patient derived DCIS mouse-intraductal (MIND) models recapitulate the full spectrum of human patient pathology and histologic features including progression to invasion in a subset of cases

Introduction: The 20-year breast cancer mortality rate following a DCIS diagnosis is ∼3%. Radiation and anti-hormonal therapy of DCIS has not resulted in improved overall survival, which argues against the non-selective use of such therapies in DCIS management. However, some DCIS cases do progress to invasive cancer, and these patients may benefit from treatment. A study of 80 DCIS patients followed for up to 30 years reported a 43% progression rate. Notably, progression was not predicted by grade, as 39% of even low-grade DCIS ultimately progressed to invasive cancer. Clearly, there is a need to identify which DCIS lesions are likely to progress. We have developed a novel mouse xenograft model (mouse-intraductal; MIND) to study the molecular basis of DCIS progression and enable identification of suitable biomarkers that predict invasive progression.

Methods: MIND involves injection of epithelial cells derived from patient breast lesions into the mammary ducts of immunocompromised mice. Serial sections of mouse mammary glands containing DCIS xenograft lesions were examined at time intervals of 3-14 months post-engraftment by histology using hematoxylin and eosin (H&E) and immunohistochemistry using anti-human cytokeratin 5/19, smooth muscle actin, ER, PR, p53, Ki67 and HER-2.

Results: Intraductal injection of cells derived from breast lesions of 28 patients into 133 mice resulted in a successful engraftment rate of 60%. Among these, 12 pure DCIS samples were injected into 35 different mice to create MIND xenografts. As early as three months post-engraftment, the DCIS xenograft cells showed multilayered in situ growth consisting of atypical neoplastic cells with prominent and vesicular nuclei. DCIS MIND xenografts exhibited the full spectrum of human DCIS histologic features, including similar biomarker expression (ER, PR, Ki67, HER-2 and p53) at long-term follow-up after engraftment (up to 12 months). Most remarkably, a subset of xenografts representing 5 patients (5/12; 42%) showed progression to invasion 6-12 months post-engraftment in the absence of any external genetic manipulations. This rate is very similar to that reported for human DCIS progression in untreated patients. MIND DCIS xenograft lesions that progressed showed disruption of basement membrane and myoepithelial layer by the invasive cells, retraction of basement membrane, and micro-invasion. MIND DCIS lesions were enriched in small capillaries, and in some cases clusters of invasive cells appeared inside nearby blood vessels.

Conclusion: The MIND xenograft is a viable model for human DCIS progression that recapitulates histologic features of human DCIS, as well as reported rates of progression to invasion. The availability of this innovative model provides a valuable tool for the discovery of new biomarkers to identify DCIS with invasive potential. The identification of high risk DCIS will ultimately help patients and clinicians choose the best course of therapy and avoid the morbidity and costs associated with unnecessary treatment.

Citation Format: Behbod F, Limback D, Hong Y, Elsarraj H, Berger J, Heddens E, Valdez K, Smith WP, Inciardi M, Reddick M, Gatewood J, Darrah J, Winblad O, Meierotto R, Ricci L, Wagner J, Amin A, May L, Cusick T, Mammen J, Fields T, Godwin AK, Fabian C, Kaufman C, Tawfik O, Fan F. Patient derived DCIS mouse-intraductal (MIND) models recapitulate the full spectrum of human patient pathology and histologic features including progression to invasion in a subset of cases [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-06-01.

ID: 113: THE ENDOTHELIAL PHD2/HIF-2 AXIS REGULATES PULMONARY ARTERY PRESSURE IN MICE

Background

Pulmonary hypertension (PH), a common clinical problem characterized by increased pulmonary artery (PA) pressure, is frequently triggered by hypoxia. Key mediators of cellular hypoxia responses are hypoxia-inducible factors (HIF)-1 and -2, the activity of which is regulated by prolyl-4-hydroxylase domain (PHD) proteins, with PHD2 being the main oxygen sensor that controls HIF activity under normoxia. Although both transcription factors are expressed in the lung, little is known about their cell type-specific roles in the pathogenesis of PH.

Methods and Results

Here we used a genetic approach to investigate the role of endothelial PHD2/HIF axis in the regulation of PA pressure. Endothelial cell specific HIF activation was achieved by crossing Vecadherin (Cdh5)-Cre transgenics to Phd2 floxed mice (ePhd2), while the contribution of each HIF isoform was assessed by generating double mutants lacking Phd2 and Hif-2 (ePhd2Hif2) or Phd2 and Hif-1 (Phd2Hif1). Right ventricular systolic pressure (RVSP) was measured via insertion of a 1.4F Mikro-tip catheter transducer into a surgically exposed right internal jugular vein. ePhd2 mice showed activation of HIF-signaling as shown by immunoblot analysis of lung tissue for HIF-1 and HIF-2. These mice developed spontaneous PH (RVSP, ePhd2: 54.3±6.9 vs Cre-: 24.8±2.2 mm Hg, P=0.005), which was associated with right ventricular hypertrophy (RVH) (Fulton Index, ePhd2: 0.52 vs Cre-: 0.28, P=0.0004) and early mortality. While morphologic analysis of ePhd2 lungs did not demonstrate plexiform or lumen-obliterating lesions, enhanced muscularization of peripheral PAs was detected in mutants compared to controls, as indicated by an increase in the number of arteries with diameters <100 µm that stained positive for αSMA (22.1±1.6 vs. 7.6±1.5 muscularized vessels/10 hpf, P<0.0001). The PH phenotype was maintained in ePhd2Hif1 mutants but was reversed in ePhd2Hif2 mutants. To assess the contribution of endothelial HIF-2 in hypoxia induced PH, endothelial Hif2 single mutants or Cre-littermates were exposed to normobaric hypoxia (10% O2) for 4 weeks. In contrast to controls, eHif2 mutants were protected from development of PH and RVH. Bone marrow transplantation studies showed no contribution from hematopoietic HIF-2 in hypoxia induced PH. Because hypoxia regulates endothelin 1 (EDN1), a potent vasoconstrictor but also apelin (APLN), a vasodilatory peptide acting through binding to the apelin G-protein-coupled receptor (APLNR), we assessed the role of endothelial HIF-2 axis in the regulation of these molecules. Endothelial deletion of Phd2 resulted in 6.4-fold induction of pulmonary Edn1 mRNA (P=0.029), but not Apln mRNA. In contrast, Aplnr was downregulated by 2.5-fold in ePhd2 mutants (P=0.037). A similar pattern of expression was detected in ePhd2Hif1 mice, whereas simultaneous deletion of Hif2a and Phd2 reversed these changes. To investigate the differences between acute and chronic hypoxia, we examined the effects of acute HIF activation on Edn1 and Apln/Aplnr gene expression in vivo. To model acute hypoxia, we subjected WT mice to 8% O2 for 48 hrs and maintained controls in room air. Acute hypoxia resulted in a 4.3-fold and 1.6-fold up-regulation of Edn1 and Apln transcripts respectively (P=0.0011 for Edn1, P=0.08 for Apln) while Aplnr was reduced by 4.3-fold (P=0.0005). We observed similar gene expression changes in mice treated with a prolyl-4-hydroxylase inhibitor (PHI) that results in global HIF activation.

Conclusions

Our studies identify endothelial HIF-2 as a key transcription factor in the pathogenesis of PH and suggest that HIF-2 regulates PA pressure by modulating the expression of vasoactive molecules. Our findings identify the PHD2/HIF2 axis as a potential target for PH therapies.

Abstract P2-05-05: Expression profiling of in vivo DCIS progression models identified BCL9 as a molecular driver of invasive progression

Introduction: There are an estimated 60,000 new cases of ductal carcinoma in situ (DCIS) each year. At present, it is not clear why some DCIS remain non-invasive for decades while others become invasive. A lack of understanding in DCIS pathobiology has led to overtreatment of more than half of DCIS patients. To identify factors that promote DCIS invasion, we have profiled the temporal molecular changes during DCIS transition to invasive ductal carcinoma (IDC) using two in vivo models, MIND (mouse-intraductal) and DCIS/IDC tandem lesions. These studies led to the identification of B cell lymphoma-9 as a potential molecular driver of early invasion. BCL9 is a newly found co-activator of Wnt-stimulated β-catenin-mediated transcription. BCL9 has been shown to promote progression of multiple myeloma and colon carcinoma. However its role in breast cancer progression had not been recognized.

Methods: Microarray and RNA sequencing were utilized to characterize the sequential and temporal changes in mRNA expression during DCIS invasive transition. BCL9 shRNA knockdown was performed to assess the role of BCL9 in in vivo invasion, EMT and canonical Wnt signaling. Immunofluorescence of 28 patient DCIS samples was used to assess a correlation between the expression of BCL9 and biomarkers of high risk DCIS. TCGA data was analyzed to assess the status of BCL9 gene alterations in 959 human breast cancers.

Results: Analysis of BCL9, by RNA and protein showed BCL9 up-regulation to be associated with DCIS transition to IDC. Analysis of patient DCIS revealed a significant correlation between high nuclear BCL9 and pathologic characteristics associated with DCIS recurrence: ER and PR negative, high nuclear grade, and high HER2. In vivo silencing of BCL9 resulted in the inhibition of DCIS invasion and reversal of epithelial-mesenchymal transition (EMT). Analysis of the TCGA data showed BCL9 gene to be altered in 26% of breast cancers. This is a significant alteration when compared to ERBB2 (19%) and ESR1 (8%). A significantly higher proportion of basal like invasive breast cancers showed BCL9 amplification.

Conclusion: BCL9 is a molecular driver of DCIS invasive progression and may predispose to the development of basal like invasive breast cancers. As such, BCL9 has the potential to serve as a biomarker of high risk DCIS and as a therapeutic target for prevention of IDC.

Citation Format: Behbod F, Elsarraj H, Hong Y, Valdez K, Chien J, Godwin A, Fields T. Expression profiling of in vivo DCIS progression models identified BCL9 as a molecular driver of invasive progression. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-05-05.

Effect of one month duration ketogenic and non-ketogenic high fat diets on mouse brain bioenergetic infrastructure

Diet composition may affect energy metabolism in a tissue-specific manner. Using C57Bl/6J mice, we tested the effect of ketosis-inducing and non-inducing high fat diets on genes relevant to brain bioenergetic infrastructures, and on proteins that constitute and regulate that infrastructure. At the end of a one-month study period the two high fat diets appeared to differentially affect peripheral insulin signaling, but brain insulin signaling was not obviously altered. Some bioenergetic infrastructure parameters were similarly impacted by both high fat diets, while other parameters were only impacted by the ketogenic diet. For both diets, mRNA levels for CREB, PGC1α, and NRF2 increased while NRF1, TFAM, and COX4I1 mRNA levels decreased. PGC1β mRNA increased and TNFα mRNA decreased only with the ketogenic diet. Brain mtDNA levels fell in both the ketogenic and non-ketogenic high fat diet groups, although TOMM20 and COX4I1 protein levels were maintained, and mRNA and protein levels of the mtDNA-encoded COX2 subunit were also preserved. Overall, the pattern of changes observed in mice fed ketogenic and non-ketogenic high fat diets over a one month time period suggests these interventions enhance some aspects of the brain's aerobic infrastructure, and may enhance mtDNA transcription efficiency. Further studies to determine which diet effects are due to changes in brain ketone body levels, fatty acid levels, glucose levels, altered brain insulin signaling, or other factors such as adipose tissue-associated hormones are indicated.

Sulforaphane induces phase II detoxication enzymes in mouse skin and prevents mutagenesis induced by a mustard gas analog

Mustard gas, used in chemical warfare since 1917, is a mutagenic and carcinogenic agent that produces severe dermal lesions for which there are no effective therapeutics; it is currently seen as a potential terrorist threat to civilian populations. Sulforaphane, found in cruciferous vegetables, is known to induce enzymes that detoxify compounds such as the sulfur mustards that react through electrophilic intermediates. Here, we observe that a single topical treatment with sulforaphane induces mouse epidermal levels of the regulatory subunit of glutamate-cysteine ligase, the rate-limiting enzyme in glutathione biosynthesis, and also increases epidermal levels of reduced glutathione. Furthermore, a glutathione S-transferase, GSTA4, is also induced in mouse skin by sulforaphane. In an in vivo model in which mice are given a single mutagenic application of the sulfur mustard analog 2-(chloroethyl) ethyl sulfide (CEES), we now show that therapeutic treatment with sulforaphane abolishes the CEES-induced increase in mutation frequency in the skin, measured four days after exposure. Sulforaphane, a natural product currently in clinical trials, shows promise as an effective therapeutic against mustard gas.

Opening the black box of cancer surgery quality: WebSMR and the Alberta experience

A web-based synoptic operative report, the WebSMR (Surgical Medical Record), was developed to define and improve the quality of cancer surgery. Surgeons accurately record the essential steps of an operation including important decision-making in an analyzable format. Outcomes can be reviewed with provincial aggregates for quality improvement and maintenance of certification. Future synoptic pathology and follow-up templates will open the "black box" of surgical processes to define quality indicators for the improvement of cancer outcomes.

Carbohydrate restriction, prostate cancer growth, and the insulin-like growth factor axis

BACKGROUND

Recent evidence suggests carbohydrate intake may influence prostate cancer biology. We tested whether a no-carbohydrate ketogenic diet (NCKD) would delay prostate cancer growth relative to Western and low-fat diets in a xenograft model.

METHODS

Seventy-five male SCID mice were fed a NCKD (84% fat-0% carbohydrate-16% protein kcal), low-fat (12% fat-72% carbohydrate-16% protein kcal), or Western diet (40% fat-44% carbohydrate-16% protein kcal). Low-fat mice were fed ad libitum and the other arms fed via a modified-paired feeding protocol. After 24 days, all mice were injected with LAPC-4 cells and sacrificed when tumors approached 1,000 mm(3).

RESULTS

Despite consuming equal calories, NCKD-fed mice lost weight (up to 15% body weight) relative to low-fat and Western diet-fed mice and required additional kcal to equalize body weight. Fifty-one days after injection, NCKD mice tumor volumes were 33% smaller than Western mice (rank-sum, P = 0.009). There were no differences in tumor volume between low-fat and NCKD mice. Dietary treatment was significantly associated with survival (log-rank, P = 0.006), with the longest survival among the NCKD mice, followed by the low-fat mice. Serum IGFBP-3 was highest and IGF-1:IGFBP-3 ratio was lowest among NCKD mice while serum insulin and IGF-1 levels were highest in Western mice. NCKD mice had significantly decreased hepatic fatty infiltration relative to the other arms.

CONCLUSIONS

In this xenograft model, despite consuming more calories, NCKD-fed mice had significantly reduced tumor growth and prolonged survival relative to Western mice and was associated with favorable changes in serum insulin and IGF axis hormones relative to low-fat or Western diet.

Beneficial effect of plasmapheresis and intravenous immunoglobulin on renal allograft survival of patients with acute humoral rejection

BACKGROUND

Acute humoral rejection (AHR) has been associated with enhanced graft loss. Our study compared the renal allograft survival of patients with AHR treated with plasmapheresis (PP) and intravenous immunoglobulin (IVIG) with allograft survival in patients with acute cellular rejection (ACR).

METHODS

We retrospectively analyzed all kidney transplants performed at our institution between January 1999 and August 2001 (n=286). Recipients were classified into three groups according to biopsy reports: AHR, ACR, or no rejection. The ACR group was further divided into early and late rejection (<90 and >90 days posttransplant, respectively).

RESULTS

After a mean follow-up of 569+/-19 days, the incidence of AHR was 5.6% (n=16). Recipient presensitization, delayed graft function, early rejection, and higher creatinine at diagnosis were characteristic of AHR. Most AHR patients (14/16) were treated with PP and IVIG. One patient received only IVIG, whereas another received only PP. All AHR patients were given steroid pulses, but only four received antilymphocyte therapy because of concomitant severe ACR. The ACR group comprised 43 patients (15%). One patient with mild rejection received no therapy, 20 improved with steroids alone, and 22 required additional antilymphocyte therapy. One-year graft survival by Kaplan Meier analysis was 81% and 84% in the AHR and ACR groups, respectively (P=NS). Outcomes remained similar when AHR patients were compared with those with early ACR.

CONCLUSIONS

We conclude that AHR, when diagnosed early and treated aggressively with PP and IVIG, carries a short-term prognosis that is similar to ACR.

Executive directors and community health centers--facing the healthcare transition

This paper examines the impressions and experiences of administrators who manage Community Health Centers (CHCs) in Region VI, US Department of Health and Human Services, with the goal of identifying leadership skills and intrinsic values that are needed to run integrated service delivery sites. As the delivery of healthcare service shifts to health promotion and disease prevention, Community Health Centers are well positioned to assume major roles in this transition. However, some CHC administrators may need additional skills in order to address the changing healthcare environment. A survey of CHC Executive Directors was conducted to identify their impressions and experiences. Information obtained from this exploratory study should be beneficial in educating the next generation of healthcare administrators.

Accuracy of fluorocrit in determination of blood perflubron concentration

Previous studies examining the radiosensitizing effects of perfluorochemical emulsions have based dose recommendations on a measurement known as fluorocrit. The fluorocrit is the proportion of blood volume occupied by perfluorochemicals and is measured using standard hematocrit procedures. This measurement is inherently crude and subject to error and variability between different individuals measuring the same sample. Furthermore, the fluorocrit method has not been compared to other quantitative methods to determine its reliability. The purpose of this study was to compare fluorocrit measurements to those obtained by gas chromatographic analysis. A 90% w/v perflubron emulsion was administered to six normal dogs once weekly for four weeks and peripheral blood samples were obtained at specified time points for analysis. A total of 123 blood samples were analyzed by both methods. The relationship between blood fluorocrit and plasma perflubron concentration measured by gas chromatography was examined using regression models. Based on the modest predictive value (r2 = 0.3683) of the derived statistical model, we conclude that fluorocrit measurement is an inaccurate method of estimation of blood perflubron concentration. Caution must, therefore, be exercised when extrapolating data and dose recommendations from reports of studies using flurocrit as the only estimate of blood perflubron concentration.

Lymphocyte recruitment and the kinetics of adhesion receptor expression during the pulmonary immune response to particulate antigen

The selectins and beta2 integrins participate in the recruitment of neutrophils in acute pulmonary inflammation. However, the cell adhesion receptors that mediate lymphocyte trafficking into the lung have not been defined. This study examined the relationship between cell adhesion molecules on the pulmonary vasculature and on lymphocytes recovered from the lung during a pulmonary immune response to intratracheal (I.T.) sheep red blood cells (SRBCs) in sensitized C57BL/6J mice. Silver-enhanced immunogold staining and reverse transcriptase polymerase chain reaction of lung tissues revealed sustained induction of VCAM-1, E-selectin, and P-selectin on the pulmonary vasculature for up to 7 days after I.T.-SRBC challenge. Neither the MECA 79 nor MECA 367 antigens were induced on the pulmonary vasculature during this period. In the peripheral blood, both CD4 and CD8 T-cell subsets showed an initial increase in P-selectin ligand expression after I.T.-SRBC challenge. The number of P-selectin ligand-positive T cells in the peripheral blood fell as T cells with both P-selectin and, to a lesser extent, E-selectin ligands accumulated in the bronchoalveolar lavage fluid. We conclude that I.T.-SRBC challenge in sensitized mice elicits prolonged synthesis of P-selectin, E-selectin, and VCAM-1 by the lung vasculature as well as selectin ligand synthesis by responding T cells. Furthermore, the entry of selectin-ligand-positive T cells into the circulation and their accumulation in the bronchoalveolar lavage fluid indicates that these receptors may contribute to T cell recruitment. Finally, VCAM-1 on the vasculature may also participate; however, the vascular addressins, required for homing to peripheral and mucosal lymphoid organs, are not essential for T-cell entry into the lung following I.T.-SRBC challenge.

Proposed mechanism of pulmonary gas trapping (PGT) following intravenous perfluorocarbon emulsion administration

PURPOSE

To investigate various hypotheses and identify the most likely mechanism preventing the complete collapse of test animal lungs at sacrifice subsequent to intravenous injection of certain perfluorocarbon emulsions.

PROTOCOL

Literature data were reviewed, experimental data were extracted from completed studies and new data were generated in an attempt to delineate reasons why, in certain animals, lungs fail to collapse normally at necropsy if previously injected with certain perfluorocarbon emulsions. The proposed hypothesis involved gas osmosis through endogenous pulmonary surfactant-liquid bridges (micro-bubbles).

RESULTS

The observed effect of incomplete lung collapse upon necropsy was found to correlate with perfluorocarbon vapor pressure. Results indicated that failure to collapse could be attributed to the formation of intra-alveolar micro-bubbles induced by the normal pulmonary elimination of perfluorocarbon vapor. These micro-bubbles result in a phenomenon which could be characterized by the term, pulmonary gas trapping. Reduction of the perfluorocarbon concentration gradient across the bubble films by exposure to a perfluorocarbon vapor-containing atmosphere was found to reduce the effect in-vivo and prevent gas osmosis bubble growth in-vitro.

CONCLUSION

Experimental observations are consistent with the proposed theory of perfluorocarbon-related gas osmosis through micro-bubbles that prevent complete lung collapse as observed upon opening the thoracic cavity of test animals.

Room temperature stable perfluorocarbon emulsions with acceptable half-lives in the reticuloendothelial system

Prolonged room temperature stability (i.e. zero particle growth) can be achieved for concentrated emulsions of perflubron (perfluorooctyl bromide) or perfluorodecalin via addition of a secondary high molecular weight, lipophilic fluorocarbon component. Due to their enhanced lipophilic character, the secondary fluorocarbon components have acceptable half-lives in the organs of the reticuloendothelial system.

Malignant evolution of penile horn

We report a rare case involving evolution of a penile horn into a neoplastic lesion. This patient was treated with surgical excision and external radiation because of the invasive characteristics of the lesion.

Breast radiography: phantom, equipment performance, and radiation dosage comparisons for twenty-eight major mammography centers in the midwest. Work in progress

This preliminary report discusses mammography tests that were conducted at 28 midwest medical centers. Equipment-parameter measurements were made, and images that were obtained with the Stanton Mark IIR Mammography Phantom were studied to compare image quality. These tests indicate that variations in equipment parameters and techniques can result in differences in the imaging of various sized phantom fibril and speck groups.

Kinin formation in hereditary angioedema plasma: evidence against kinin derivation from C2 and in support of "spontaneous" formation of bradykinin

Hereditary angioedema (HAE) is due to a functional deficiency of the inhibitor of the activated first component of complement (C1 INH). This abnormality is thought to be responsible for the generation of a kininlike peptide in HAE plasma that is derived from the second component of complement (C2). Specifically, a combination of C2 cleavage by C1s and C2 fragment cleavage by plasmin has been reported to generate a kinin that is distinguishable from bradykinin. We have attempted to generate this peptide by activating the classical complement pathway by incubation of plasma with immune complexes and then adding plasmin or by incubating purified C1s with C4 and C2 and then adding either plasmin or trypsin. We performed a total of 13 experiments, and in no case was a kininlike molecule generated as assessed by contraction of the estrus rat uterus. However, incubation of EDTA-treated HAE plasma at 37 degrees C for time intervals up to 1 hr progressively generated a smooth muscle-contracting activity. This activity was resistant to tryptic digestion but was destroyed after incubation with carboxypeptidase B, an inhibition profile consistent with that of bradykinin. We therefore propose that bradykinin alone, or in combination with other factors heretofore unrecognized, might be responsible for the swelling that is characteristic of hereditary angioedema.

Improved cognition after external carotid endarterectomy

Recent clinical results support the conclusion that internal carotid endarterectomy not only serves as a prophylactic measure against catastrophic stroke, but may improve cognitive functioning as well. Improvement in cognitive testing after internal carotid endarterectomy has been amply substantiated in recent literature. 3, 4, 5, 8, This report illustrates that improvement in cerebral blood flow by any means is equally effective in improving cerebral function.

Purine and pyrimidine pool sizes and purine base utilization in human lymphocytes and cultured lymphoblasts

Purine base metabolism and purine ribonucleotide interconversions were compared in three lines of cultured human lymphoblasts as well as in normal human peripheral lymphocytes which were isolated by the Ficoll–Hypaque centrifugation procedure. In all cases, conversion of the purine base to the ribonucleoside monophosphate appeared to be rate-limiting. The relative rates of ATP and GTP synthesis from hypoxanthine were observed to vary in the different cells examined. Purine and pyrimidine ribonucleotide pool sizes, as determined by high-pressure liquid chromatography, are presented for the cultured cell lines.