Abstract 3645: The splanchnic mesenchyme is the main tissue origin of fibroblasts in the pancreas during homeostasis and tumorigenesis

In pancreatic ductal adenocarcinoma (PDAC), cancer associated fibroblasts (CAFs) play critical and complex roles in the tumor microenvironment. CAFs are also a major cell type in the desmoplastic stroma in PDAC and may account for half of the entire tumor tissue. Multiple subtypes of CAFs have been suggested, but the tissue origin(s) of CAF subtypes are unknown and genetic tools to robustly target them in vivo are lacking. Here we aimed to examine three potential tissue sources of CAFs: the pancreatic epithelium (through epithelium-to-mesenchyme transition), the bone marrow (through circulation), and the pancreatic tissue resident fibroblasts (TRFs) in the normal pancreas (through proliferation). We utilized a genetically engineered mouse model of PDAC, where Kras and p53 mutations were engineered in the pancreatic epithelium using an Flp-Frt system. To determine whether the pancreatic epithelium gives rise to CAFs, we permanently labeled the pancreatic epithelium with a GFP reporter and traced their cell descendants by GFP expression. Despite robust GFP labeling of the epithelium, GFP expression was rarely identified in CAFs, suggesting little contribution of epithelium to the CAF pool. To determine whether the bone marrow gives rise to CAFs, we transplanted donor bone marrow carrying a ubiquitously expressed GFP reporter allele to GFP-negative recipient mice. We found that only a small portion of pancreatic CAFs were tagged with GFP. Lastly, to determine whether pancreatic TRFs give rise to CAFs, we used an inducible CreER-LoxP system to allow for permanent Tomato labeling in TRFs progenitors, the splanchnic mesenchyme, during mid-gestation. Lineage tracing in PDAC showed that the vast majority of CAFs were labeled with Tomato expression, suggesting their splanchnic origin. Furthermore, certain splanchnic gene expression signatures were persistent in subsets of CAFs in both the PDAC mouse model and human patient samples. In summary, we found that bone marrow contributes to a small portion of CAFs in PDAC, and the pancreatic epithelium contributes even less. Meanwhile, pancreatic TRFs are derived from the splanchnic mesenchyme during fetal development and they expand to contribute to the vast majority of CAFs in PDAC. Moreover, the persistence of splanchnic signature defines subtypes of CAFs. This study provides approaches to robustly target CAFs in vivo, and novel insights into CAF origin and heterogeneity in PDAC.

Citation Format: Lu Han, Yongxia Wu, Melodie Parrish, Khushbu Patel, Tony Trimboli, Julia Lefler, Xuezhong Yu, Michael Zimmermann, Angela Mathison, Raul Urrutia, Michael Ostrowski, Gustavo Leone. The splanchnic mesenchyme is the main tissue origin of fibroblasts in the pancreas during homeostasis and tumorigenesis [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 3645.

Factors influencing low incidence of living donors for renal transplantation in Poland

PURPOSE OF THE STUDY

To answer the question: "Why are only 3.8% of kidney transplantations in Poland from living donors?"

MATERIAL AND METHODS

The research was conducted using data from anonymous polls addressed to family members of dialyzed patients (potential donors).

RESULTS

Almost everybody (98%) had heard about the possibility of treating renal insufficiency by kidney transplantation, but only 77% knew about the possibility of giving their own kidney to a related person. Merely 36% had been informed about this treatment method by a doctor. The most common fears within respondents were those of: health worsening after donating a kidney--45%, and the operation itself (taking an organ)--39%.

Profiling of collagen and extracellular matrix deposition from cell culture using in vitro ExtraCellular matrix mass spectrometry imaging (ivECM-MSI)

While numerous approaches have been reported towards understanding single cell regulation, there is limited understanding of single cell production of extracellular matrix phenotypes. Collagens are major proteins of the extracellular microenvironment extensively used in basic cell culture, tissue engineering, and biomedical applications. However, identifying compositional regulation of collagen remains challenging. Here, we report the development of In vitro ExtraCellular Matrix Mass Spectrometry Imaging (ivECM-MSI) as a tool to rapidly and simultaneously define collagen subtypes from coatings and basic cell culture applications. The tool uses the mass spectrometry imaging platform with reference libraries to produce visual and numerical data types. The method is highly integrated with basic in vitro strategies as it may be used with conventional cell chambers on minimal numbers of cells and with minimal changes to biological experiments. Applications tested include semi-quantitation of collagen composition in culture coatings, time course collagen deposition, deposition altered by gene knockout, and changes induced by drug treatment. This approach provides new access to proteomic information on how cell types respond to and change the extracellular microenvironment and provides a holistic understanding of both the cell and extracellular response.

What is the legal 'standard of medical care' when there is no standard medical care? A survey of the use of home apnea monitoring by neonatology fellowship training programs in the United States

In treating a patient, a doctor is obliged to use the skill and care that is ordinarily used by reasonably well-qualified doctors in similar cases. In addition, the only way in which a juror may decide whether the defendant used the skill and care which the law required of him or her is from evidence presented by doctors called as expert witnesses (cf Illinois Pattern Jury Instructions). However, what should be done if expert opinions differ concerning the care that is "ordinarily used"? Home apnea monitoring (HAM) is prescribed at times for graduates of neonatal intensive care units despite the fact that indications for its use are not well established and efficacy is completely unknown. The authors attempted to determine standards for HAM as it is currently practiced in neonatology training programs. The primary teaching hospital for each of the 99 neonatology training programs in the United States was identified. Both the medical director (MD) and a neonatal intensive care unit nurse manager (RN) were asked about the use of HAM in their own nursery for four clinical vignettes. Each vignette depicted a 1000-g birth weight infant, currently 7 weeks old and ready for discharge. In three vignettes, the infant had demonstrated no apnea, mild apnea (resolved by 2 weeks of age), or moderate apnea (requiring theophylline therapy at discharge) during the hospital course. In the fourth vignette, the infant had no apnea but was to be discharged home with supplemental oxygen. For 67 of 99 training programs, paired responses of RN managers and MD directors were obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract 1344: myCAFs and iCAFs have similar lineage

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense stroma primarily composed of cancer associated fibroblasts (CAFs). These fibroblasts are a diverse population of cells; some groups of fibroblasts have been shown to play tumor supporting roles while others have been shown to be tumor suppressing. Two prolific and well-characterized CAF subtypes—myofibroblasts (myCAFs) and inflammatory CAFs (iCAFs)—could potentially have different regulatory effects on tumor growth. Understanding the tissue origin of these two groups of CAFs could assist in understanding the complex and heterogeneous roles they might play in PDAC development. Previous studies in our group showed that the splanchnic mesenchyme, a layer of mesenchyme adjacent to the fetal pancreatic epithelium, gives rise to the majority of the total CAF population. Here, I aim to test the hypothesis that both iCAFs and myCAFs originate from the splanchnic mesenchyme. myCAFs have been previously observed to be proximal to tumor cells and express αSMA at a higher level, while iCAFs have been observed to be distal to tumor cells and express αSMA at a lower level. Here, we used a genetically engineered mouse PDAC model carrying KrasG12D/+;p53Frt/+;Pdx1FlpO/+;Isl1cre/+;R26Tomato/+ alleles. In this model, epithelial specific FlpO expression leads to Kras activation and p53 deletion, causing tumorigenesis. Simultaneously, splanchnic specific Cre expression leads to permanent tomato expression in the splanchnic descendants. The pancreata of these mice were harvested, fixed, and mounted onto slides. Co-immunostaining with αSMA and tomato was then done. The stained slides were scanned, and the Inform software was used to segment and phenotype the cells. More than 95% of αSMA high cells were tomato positive, and more than 95% of αSMA low cells were also tomato positive. We thus conclude that both myCAFs and iCAFs originate from the splanchnic mesenchyme. Consistent with previous in vitro studies, this lineage tracing study suggests that different CAF subtypes are likely due to patterning influenced by different factors within the tumor microenvironment.

Citation Format: Thomas S. Walter, Lu Han, Michael Ostrowski. myCAFs and iCAFs have similar lineage [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1344.

[Evaluation of right ventricular function using radioisotope angiography in patients with chronic obstructive pulmonary disease]

The aim of the study was the evaluation of equilibrium gated blood pool angiography in noninvasive assessment of right ventricular ejection fraction in 50 patients with chronic obstructive pulmonary disease. The degree of ventilatory disturbances was measured using plethysmography to calculate air flow indexes--FEV1, MEF50 and Rt and gasometric values of arterialized capillary blood--PaO2, PaCO2, pH. The used method allowed calculation of RVEF in 41 patients, which were divided into three groups according to presence of symptoms of right ventricular failure and RVEF values. In 12 patients free of RV failure symptoms RVEF was decreased (below 40%). Basing on results of this study the authors believe that this method is useful in diagnosing subclinical states of RV failure.

[Use of Hammer type external fixators for pelvic fractures--case report]

A case of comminuted pelvic fracture with marked displacement of the fragments complicated by extensive genitourinary injury is presented. Pelvic ring was reconstructed and stabilized with Hammer external fixator; the fracture united without complications.

The influence of the tumor necrosis factor-alpa-308G>A polymorphism on the efficacy of immunosuppressive therapy in patients after kidney transplantation

Cytokines play an important role in the immune response. The calcineurin inhibitors (cyclosporine CsA, tacrolimus TAC) widely used after renal transplantation to prevent allograft rejection are immunosuppressive drugs suppressing the production of cytokines. These drugs are characterized by interindividual variability and require monitoring their blood concentrations to predict their optimal dosage. Therefore, the aim of the study was to determine the correlation between therapeutic effects of immunosuppressants and the tumor necrosis factor-α (TNF-α)-308G>A polymorphism in renal transplant patients. A total of 412 patients receiving TAC and CsA were included in the study. Genotype frequencies were determined using the real-time PCR method. Patients with the GG genotype received higher doses of TAC as compared to carriers of the GA genotype (5.24 mg versus 3.35 mg) and had lower mean drug concentration in blood (5.86 ng/ml versus 6.92 ng/ml). Similar results were also obtained for CsA (GG: 185.33 mg versus GA: 153.30 mg, P < 0.05). The comparison of the TNF-α-308G>A polymorphism with the biochemical parameters did not reveal a potential risk for transplant rejection. These results indicate that the TNF-α-308G>A polymorphism may influence the dosage of immunosuppressive drugs in patients after transplantation as far as individualization of drug therapy is concerned.

Search for Dark Matter Annihilation Signals in the H.E.S.S. Inner Galaxy Survey

The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented γ-ray survey of the Galactic Center (GC) region, i.e., the Inner Galaxy Survey, at very high energies (≳100  GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant γ-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section ⟨σv⟩. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach ⟨σv⟩ values of 3.7×10^{-26}  cm^{3} s^{-1} for 1.5 TeV DM mass in the W^{+}W^{-} annihilation channel, and 1.2×10^{-26}  cm^{3} s^{-1} for 0.7 TeV DM mass in the τ^{+}τ^{-} annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based γ-ray observations thus probe ⟨σv⟩ values expected from thermal-relic annihilating TeV DM particles.

High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System, covering 2 orders of magnitude in energy and reaching a proton rejection power of better than 10^{4}. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from Γ_{1}=3.25±0.02(stat)±0.2(sys) to Γ_{2}=4.49±0.04(stat)±0.2(sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms.

The impact of a private group practice of converting to an automated medical information system

As hardware and software developments make medical information systems increasingly available to physicians office practices and outpatients facilities, there is a need to focus on systems installation and conversion issues. In addition to the detailed step-by-step implementation plan, the overall impact of the new system should be anticipated. The purchasers should consider such issues as new information flow and user communication patterns between patient care and ancillary and support departments; restructuring of fundamental approaches to work allocation for either batch or real-time systems; and new emphasis on any departments vital to problem-spotting and solving. At California Primary Physicians (CPP), an awareness of these changes did not develop until well after the official "live" data had passed and the staff had been successfully using the system for several months. This paper explains how the above issues have emerged and the impact they have had on CPP, and provides a framework for anticipating such matters in any system installation.

Comparative gross and histological effects of the CO2 laser, Nd-YAG laser, scalpel, Shaw scalpel and cutting cautery on skin in rats

Surgical instruments capable of sealing blood vessels while incising skin were compared to standard scalpel incisions in rats and the resultant scars examined in the early stages of wound healing for both gross and histological appearances. Those instruments which provide for hemostasis appear to do so with a delay in the early phases of wound healing.

Correlation Between Percentage of Immuncompetent CD4+ and CD4+CD25+ Cells and Compatibility in the HLA System and Selected Parameters Assessing Transplanted Kidney Function

BACKGROUND

Long-term kidney allograft survival is affected by many coexisting immunologic factors. Currently, only two basic immunologic parameters-HLA compatibility and panel reactive antibodies-are routinely used in kidney transplantation management. At the same time, there is a great need for immunologic biomarkers that will help inrease understanding of kidney transplant immunology and improve clinical care of kidney recipients. T regulatory cells (Tregs) represent one of the major targets of this approach. The aim of this study was to investigate possible simple associations between Tregs count in recipients' blood and other routinely assessed or easily accessible laboratory parameters.

METHODS

Laboratory outcomes from medical files of transplant outpatient clinic in combination with flow cytometry analyses of particular immunocompetent cells populations were used. Flow cytometry was used to calculate Tregs recognized as TCD4⁺CD25^high. The Spearman rank correlation test was used to verify particular associations.

RESULTS

A negative correlation was found beween HLA compatibility and Tregs count as well as between platelets count and Tregs count.

CONCLUSIONS

Whereas the negative correlation between Tregs and platelets counts may possibly mirror some recent findings in basic research, a negative correlation between HLA compatibility and Tregs points the direction of further research to factors triggering post-transplant immune tolerance.

Organ procurements in West Pomerania in years 2000-2001

Year by year the actual number of transplanted organs has been growing in Poland. In the event of the Województwo Zachodniopomorskie (Western Pomeranian Province) the primary activities were focused on informing medical personnel at hospital departments about approaching donors through trainings for such medical personnel. Such activities resulted in both acceptance and support, especially by medical personnel of medium as well as lower ranks. Since 1983 two transplant units have been functioning in the Province: SPSK-2 and S. P. W. S. Z. in Szczecin, and since 2000 two co-ordination offices, too. Main result of our activities can be seen in the number of organs procured for transplantation. In 2000 we had 27.7 procurements per million (ppm), in 2001 there were 39.9 ppm.

Outcomes of kidney transplantation during the SARS-CoV-2 pandemic at one centre in Poland

The SARS-CoV-2 pandemic has significantly affected the number of transplanted organs worldwide. The rules and restrictions related to transplantation activities in Poland are included in the updated guidelines of the Polish Organizational and Coordination Centre for Transplantation. Our clinic faces the same problems as the rest of the hospitals in the country. Not only are the number of recipients falling, but there are also numerous restrictions concerning, among other things, qualification of donors and recipients and even preparation of centers for long-term care in the event of infection of organ recipients with the SARS-CoV-2 virus. Statistics showed, after an initial fall in the number of kidneys transplanted, a temporary normalization during the summer months, only to record a fall again with an increase in new cases of COVID-19. A total of 29 kidneys were transplanted at our center between March and December 2020. Kidney transplantation is not only linked to the operation itself, but also to the follow-up care of the recipients. Reduced immunity among recipients due to immunosuppressive treatment as well as comorbidities among recipients contribute to this group being at increased risk of symptomatic SARS-CoV-2 infection. The number of cases of SARS-CoV-2 infection among kidney transplant recipients at our center was 7, of which we recorded 2 deaths due to COVID-19 in the period after kidney transplant. Postoperative complications probably related to previous SARS-CoV-2 infection occurred in 1 patient.

The effect of gastrectomy on pharmacokinetics of orally administered paracetamol in man

Pharmacokinetics of paracetamol was investigated after administration of a single oral dose in patients with gastric and duodenal ulcers shortly before surgery and 4 weeks after partial Reichel-Poly gastrectomy. The course of changes of paracetamol concentrations was described with a two compartment model for extravascular administration. The calculations were carried out with an Odra 1300 computer. After gastrectomy the absorption of paracetamol was significantly depressed, particularly in patients with duodenal ulcers.

Abstract 2841: Inducible modulation of NF-kappaB in macrophages reveals that timing of intervention may be critical to therapeutic outcome during mammary tumorigenesis

Elevated levels of NF-kappaB signaling are associated with multiple cancers. Therefore, it is not surprising that inhibitors of NF-kappaB are being investigated as potential therapeutics. While extensive efforts are being made to identify inhibitors there is less focus on investigating the effects of inhibition in specific cell types and during defined stages of tumor progression. We have developed murine transgenic models that enable us to induce expression of an activator or inhibitor of NF-kappaB in macrophages, by adding doxycycline to the drinking water of mice. We have combined these with the Polyoma model of mammary cancer to investigate the effects of modulation of NF-kappaB signaling specifically within macrophages. Given several recent publications we were predicting that activation of NF-kappaB would have pro-tumor effects. However, using a tail vein injection model, our data identifies a stage during progression in which activation of NF-kappaB in macrophages significantly limits metastasis. Activation of NF-kappaB alters immune cell populations and results in rapid killing of tumor cells during the seeding phase. In this model inhibition of NF-kappaB in macrophages during this critical stage of metastasis is pro-tumor. This suggests that while inhibition of NF-kappaB at later stages of tumor progression may have therapeutic benefit, inhibition during the seeding phase my lead to the opposite effect. Our studies highlight the importance of continued investigation into aspects of cell specificity and timing that may change the potential outcome of a clinical trial using NF-kappaB inhibitors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2841. doi:10.1158/1538-7445.AM2011-2841