Mesenchymal stromal cells with chimaeric antigen receptors for enhanced immunosuppression

Allogeneic mesenchymal stromal cells (MSCs) are a safe treatment option for many disorders of the immune system. However, clinical trials using MSCs have shown inconsistent therapeutic efficacy, mostly owing to MSCs providing insufficient immunosuppression in target tissues. Here we show that antigen-specific immunosuppression can be enhanced by genetically modifying MSCs with chimaeric antigen receptors (CARs), as we show for E-cadherin-targeted CAR-MSCs for the treatment of graft-versus-host disease in mice. CAR-MSCs led to superior T-cell suppression and localization to E-cadherin+ colonic cells, ameliorating the animals' symptoms and survival rates. On antigen-specific stimulation, CAR-MSCs upregulated the expression of immunosuppressive genes and receptors for T-cell inhibition as well as the production of immunosuppressive cytokines while maintaining their stem cell phenotype and safety profile in the animal models. CAR-MSCs may represent a widely applicable therapeutic technology for enhancing immunosuppression.

CD19 occupancy with tafasitamab increases therapeutic index of CART19 cell therapy and diminishes severity of CRS

ABSTRACT

In the development of various strategies of anti-CD19 immunotherapy for the treatment of B-cell malignancies, it remains unclear whether CD19 monoclonal antibody therapy impairs subsequent CD19-targeted chimeric antigen receptor T-cell (CART19) therapy. We evaluated the potential interference between the CD19-targeting monoclonal antibody tafasitamab and CART19 treatment in preclinical models. Concomitant treatment with tafasitamab and CART19 showed major CD19 binding competition, which led to CART19 functional impairment. However, when CD19+ cell lines were pretreated with tafasitamab overnight and the unbound antibody was subsequently removed from the culture, CART19 function was not affected. In preclinical in vivo models, tafasitamab pretreatment demonstrated reduced incidence and severity of cytokine release syndrome and exhibited superior antitumor effects and overall survival compared with CART19 alone. This was associated with transient CD19 occupancy with tafasitamab, which in turn resulted in the inhibition of CART19 overactivation, leading to diminished CAR T apoptosis and pyroptosis of tumor cells.

AXL Inhibition Improves the Antitumor Activity of Chimeric Antigen Receptor T Cells

The receptor tyrosine kinase AXL is a member of the TYRO3, AXL, and proto-oncogene tyrosine-protein kinase MER family and plays pleiotropic roles in cancer progression. AXL is expressed in immunosuppressive cells, which contributes to decreased efficacy of immunotherapy. Therefore, we hypothesized that AXL inhibition could serve as a strategy to overcome resistance to chimeric antigen receptor T (CAR T)-cell therapy. To test this, we determined the impact of AXL inhibition on CD19-targeted CAR T (CART19)-cell functions. Our results demonstrate that T cells and CAR T cells express high levels of AXL. Specifically, higher levels of AXL on activated Th2 CAR T cells and M2-polarized macrophages were observed. AXL inhibition with small molecules or via genetic disruption in T cells demonstrated selective inhibition of Th2 CAR T cells, reduction of Th2 cytokines, reversal of CAR T-cell inhibition, and promotion of CAR T-cell effector functions. AXL inhibition is a novel strategy to enhance CAR T-cell functions through two independent, but complementary, mechanisms: targeting Th2 cells and reversing myeloid-induced CAR T-cell inhibition through selective targeting of M2-polarized macrophages.

Hyperphosphorylated PTEN exerts oncogenic properties

PTEN is a multifaceted tumor suppressor that is highly sensitive to alterations in expression or function. The PTEN C-tail domain, which is rich in phosphorylation sites, has been implicated in PTEN stability, localization, catalytic activity, and protein interactions, but its role in tumorigenesis remains unclear. To address this, we utilized several mouse strains with nonlethal C-tail mutations. Mice homozygous for a deletion that includes S370, S380, T382 and T383 contain low PTEN levels and hyperactive AKT but are not tumor prone. Analysis of mice containing nonphosphorylatable or phosphomimetic versions of S380, a residue hyperphosphorylated in human gastric cancers, reveal that PTEN stability and ability to inhibit PI3K-AKT depends on dynamic phosphorylation-dephosphorylation of this residue. While phosphomimetic S380 drives neoplastic growth in prostate by promoting nuclear accumulation of β-catenin, nonphosphorylatable S380 is not tumorigenic. These data suggest that C-tail hyperphosphorylation creates oncogenic PTEN and is a potential target for anti-cancer therapy.

Abstract 5074: Addition of MAPK inhibitors to prime and sensitize poorly differentiated thyroid cancers as a strategy to improve TSHR-CART cell therapy antitumor activity

Thyroid cancer is the most common endocrine cancer in the US, and its incidence is rising. Most thyroid cancer deaths are attributed to treatment-refractory, metastatic tumors. Thyroid stimulating hormone receptor (TSRH) expression is largely limited to the thyroid gland and is abundantly expressed on thyroid tumor cells, making TSRH a compelling target for advanced thyroid cancer diagnostics and therapeutics. Therefore, we developed a novel TSHR-targeted chimeric antigen receptor (CAR) T cell therapy to treat aggressive thyroid cancers. TSHR-CAR constructs were cloned into a lentiviral CAR construct containing 4-1BB and CD3ζ. First, we demonstrated potent TSHR-CART antigen-specific anti-tumor activity in vitro. Then, NOD-SCID-γ-/- (NSG) mice were inoculated subcutaneously with TSHR+ tumor cells and randomized by tumor volume to treatment with TSHR-CART cells or control Untransduced T cells (UTD). Treatment with TSHR-CART cells resulted in dose-dependent antitumor activity and prolonged survival. De-differentiated anaplastic thyroid cancers (ATC) downregulate TSHR. Our TSHR immunohistochemistry results corroborated these findings and displayed minimal TSHR protein expression, precluding successful TSHR-CART treatment. We therefore sought to sensitize these tumors with MAPK inhibitors, as a strategy to upregulate TSHR expression in patients with metastatic thyroid cancer. TSHR expression was upregulated in patient-derived xenograft (PDX) ATC models after one week of daily administration of the MAPK inhibitors (p=0.0024). After confirming that MAPK inhibition does not dampen TSHR-CART effector functions, we tested sequential and combination therapy of TSHR-CART with MEK and BRAF inhibition in vivo. NSG mice were engrafted with ATC BRAF-mutant PDX tumors and randomized by tumor volume to daily oral treatment with placebo or trametinib (MEK inhibitor) plus dabrafenib (BRAF inhibitor). One week later, mice received either UTD or TSHR-CART. Mice conditioned with trametinib plus dabrafenib (p=0.0018) and subsequently treated with TSHR-CART showed superior antitumor activity. However, the improved antitumor activity in this setting was transient. We therefore tested the durability of TSHR upregulation following MEK/BRAF inhibition and demonstrated that TSHR upregulation lasts less than 48-72 hours after discontinuation. Finally, we tested the combination of TSHR CART cells with MEK/BRAF inhibitors in ATC BRAF-mutant PDX tumors. Here, combining TSHR-CART cells with MEK/BRAF inhibitors result in durable control of the tumors. Collectively, our findings indicate that MEK/BRAF inhibition of de-differentiated thyroid cancers upregulated TSHR expression and enhanced TSHR-CART antitumor activity. This work represents a viable strategy to improve outcomes of patients with aggressive, metastatic thyroid cancers.

Citation Format: Claudia Manriquez Roman, Kendall J. Schick, Justyna J. Gleba, Truc N. Huynh, Elizabeth L. Siegler, James L. Miller, Aylin Alasonyalilar Demirer, Matthew L. Pawlush, Ahmet Biligili, Long K. Mai, Erin Tapper, Leo R. Sakemura, Michelle J. Cox, Carli M. Stewart, Ismail Can, Ekene J. Ogbodo, Gaofeng Cui, Georges Mer, Gloria R. Olivier, Yushi Qiu, Robert C. Smallridge, Zubair C. Abba, Han W. Tun, John A. Copland, Saad S. Kenderian. Addition of MAPK inhibitors to prime and sensitize poorly differentiated thyroid cancers as a strategy to improve TSHR-CART cell therapy antitumor activity. [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 5074.

Abstract 4082: Impact of immunosuppressive monocytes on CART19 cell effector functions and outcomes

CD19 directed chimeric antigen receptor T (CART19) cell therapy has resulted in remarkable outcomes in B cell malignancies and was FDA approved in multiple indications. However, durable remissions are limited to 40% of treated patients. Inhibitory myeloid cells in tumor microenvironment have been found to suppress T cell expansion and contribute to failure of CART19 cell therapy. In this study, we aimed to unravel the interactions between monocytes, CART19 cells and tumor cells to understand how monocytes-CART19 cell interactions impact CART19 cell effector functions and clinical outcomes. Two sets of experiments were conducted, 1) use of healthy CART19 cells, CD19+ tumor cells, and healthy monocytes; 2) use of brexu-cel products from ZUMA-2 clinical trial treating mantle cell lymphoma (MCL), patient-matched monocytes and circulating MCL tumor cells (n = 11; 6 durable responders, 2 relapsed after initial response and 3 non-responders).

CD28 costimulated CART19 (CART19-28ζ) cells generated in the lab from healthy donors were co-cultured with donor freshly isolated monocytes in the presence of Jeko-1 cells (a CD19+ MCL cell line). CART19 antigen specific proliferation was not inhibited by freshly isolated monocytes. When monocytes were co-cultured with CART19 and tumor cells, higher levels of eotaxin, GRO, MCP-3 and IL-7 were detected. When CART19 cells were co-cultured with the CD19+ JeKo-1 cells in the presence of ex vivo M2 polarized macrophages, CART19 antigen specific proliferation was inhibited (p=0.0045). Transwell experiments demonstrate that M2-induced CART19 inhibition is not contact dependent. Cytokine profile analysis indicated increased level of IL-1ra, IP-10 and MCP-1 and decreased level of IL-17A, sCD40L, IL-9 and MIP-1α when M2 macrophages were co-cultured with CART19 and tumor cells compared to co-cultures of tumor cells and CART19.

Then we conducted ex vivo co-cultures of brexu-cel products, autologous monocytes and circulating MCL tumor cells from MCL patients (ZUMA-2) collected prior to CART19 cell infusion. Here we observed trends of elevation of IL-13 and IL-5 and reduction of GRO, MCP-3, MIP-1β and IL-8 in non-responders, compared to responders (durable responses or relapsed patients).

Our results support that monocyte- and macrophage-dependent cytokine release could modulate CART19 effector and trafficking functions, and thus CART19 clinical outcomes. This warrants further investigation around strategies to improve durable responses to CART cell therapy.

Citation Format: Kun Yun, Reona Leo Sakemura, Michelle J. Cox, Truc Huynh, Claudia Manriquez-Roman, Olivia Sirpilla, Carli M. Stewart, James H. Girsch, Ekene J. Ogbodo, Ismail Can, Brooke Kimball, Lionel A. Kankeu Fonkoua, Mehrdad Hefazi, Michael W. Ruff, Elizabeth L. Siegler, Mike Mattie, Sao-Mai Nguyen-Mau, Simone Filosto, Saad S. Kenderian. Impact of immunosuppressive monocytes on CART19 cell effector functions and outcomes. [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 4082.

Abstract 1153: IL-4 depletion leads to the improvement of CART cell therapy

While chimeric antigen receptor T-cell therapy targeting CD19 (CART19) has shown remarkable success in the treatment of hematological malignancies, the durable response rates remain approximately 40% and there are limited solutions for CART cell therapy in the treatment of solid tumors. To further understand mechanisms of resistance, including CART cell exhaustion, we employed three independent approaches: 1) RNA and ATAC sequencing on unstimulated vs. exhausted healthy donor CART19 cells by utilizing an in vitro model for exhaustion, 2) RNA and ATAC sequencing on pre-infusion CART19 cell products from responders and non-responders in the Zuma-1 clinical trial that led to the FDA approval of axi-cel CART19 therapy, and 3) a genome-wide CRISPR knockout screen in healthy donor CART19 cells using our in vitro model for exhaustion.

In each of these approaches, IL-4 was identified as a regulator of CART cell dysfunction. In approach 1, ingenuity pathway analysis of genes that were both differentially accessible and expressed in exhausted compared with unstimulated CART19 cells revealed IL-4 as a top upstream regulator (p = 5E-6). In approach 2, IL-4 was one of two genes that were both upregulated and more accessible in CART19 cell products from non-responders (p < 5E-2). Finally, in approach 3, gene ontology enrichment analysis of genes that were positively selected during the genome-wide CRISPR knockout screen, revealed regulation of the IL-4 pathway as one of the top affected pathways (p = 1E-4).

Together, our data indicates a role for IL-4 in CART cell dysfunction caused by exhaustion. Investigating this mechanism further, we saw an increase in the production of IL-4 as CART cells became exhausted (p = 4E-3). Treatment of CART19 cells with human recombinant IL-4 (hrIL-4) resulted in dysfunction as evident by a decrease in antigen specific cytotoxicity (p = 4E-3) and proliferative ability (p= 6.5E-2), as well as exhaustion-specific signs of dysfunction such as an increase in the expression of the inhibitory receptor, TIM-3 (p = 3E-3) and an increase in the transcription of the exhaustion-related transcription factor EOMES (p = 1E-2).

Finally, we tested whether IL-4 neutralization enhances CART19 cell functions. Using a CD19+ JeKo-1 xenograft mouse model, we compared the combination treatment of CART19 cells and an IL-4 neutralizing monoclonal antibody (10 mg/Kg, clone # MP4-25D2) to CART19 cells and an IgG control. IL-4 neutralization in combination with CART19 cells resulted in reduced tumor burden (p = 4.6E-2), increased CART cell proliferation (p = 8E-3), and prolonged overall survival (p= 5E-2). In summary, our data indicates that 1) IL-4 induces CART cell dysfunction through a state of exhaustion and 2) IL-4 neutralization with a monoclonal antibody enhances CART cell therapy. As such, this novel combination therapy holds the potential to be translated to the clinic to improve durable responses from CART cell therapy.

Citation Format: Carli Stewart, Michelle J. Cox, Reona Sakemura, Ekene J. Ogbodo, Ismail Can, Claudia Manriquez Roman, Kun Yun, Olivia Sirpilla, James H. Girsch, Truc Huynh, Elizabeth L. Siegler, Jenny J. Kim, Mike Mattie, Nathalie Scholler, Simone Filosto, Saad S. Kenderian. IL-4 depletion leads to the improvement of CART cell therapy [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 1153.

Targeting cancer-associated fibroblasts in the bone marrow prevents resistance to CART-cell therapy in multiple myeloma

Pivotal clinical trials of B-cell maturation antigen-targeted chimeric antigen receptor T (CART)-cell therapy in patients with relapsed/refractory multiple myeloma (MM) resulted in remarkable initial responses, which led to a recent US Food and Drug Administration approval. Despite the success of this therapy, durable remissions continue to be low, and the predominant mechanism of resistance is loss of CART cells and inhibition by the tumor microenvironment (TME). MM is characterized by an immunosuppressive TME with an abundance of cancer-associated fibroblasts (CAFs). Using MM models, we studied the impact of CAFs on CART-cell efficacy and developed strategies to overcome CART-cell inhibition. We showed that CAFs inhibit CART-cell antitumor activity and promote MM progression. CAFs express molecules such as fibroblast activation protein and signaling lymphocyte activation molecule family-7, which are attractive immunotherapy targets. To overcome CAF-induced CART-cell inhibition, CART cells were generated targeting both MM cells and CAFs. This dual-targeting CART-cell strategy significantly improved the effector functions of CART cells. We show for the first time that dual targeting of both malignant plasma cells and the CAFs within the TME is a novel strategy to overcome resistance to CART-cell therapy in MM.

Challenges of CAR T-cell Therapy in CLL: Lessons Learned

Development of chimeric antigen receptor T (CART) cell therapy has led to unprecedented success against B cell leukemia and lymphoma and resulted in FDA-approved treatment protocols. Despite the initial clinical response in B cell-related malignancies, high relapse rates suggest that much work is needed to uncover mechanisms of resistance. In chronic lymphocytic leukemia (CLL), the durable activity of CAR T-cells is limited, and CART cell success is lower than in other malignancies. T cells from these patients are vulnerable to a state of dysfunction due to stresses including chronic infection, rapid cell cycle upon antigen recognition, immunosuppressive tumor microenvironment, and cancer-related treatments. T cells are also introduced to additional stresses when cultured ex vivo during the CART manufacturing process. All these factors contribute to the limited regenerative capacity of T cells, which can lead to CART treatment failure. In this short report, we will review the challenges of CAR T-cell therapy in patients with CLL and discuss potential strategies to overcome these challenges.

p21 produces a bioactive secretome that places stressed cells under immunosurveillance

Immune cells identify and destroy damaged cells to prevent them from causing cancer or other pathologies by mechanisms that remain poorly understood. Here, we report that the cell-cycle inhibitor p21 places cells under immunosurveillance to establish a biological timer mechanism that controls cell fate. p21 activates retinoblastoma protein (Rb)–dependent transcription at select gene promoters to generate a complex bioactive secretome, termed p21-activated secretory phenotype (PASP). The PASP includes the chemokine CXCL14, which promptly attracts macrophages. These macrophages disengage if cells normalize p21 within 4 days, but if p21 induction persists, they polarize toward an M1 phenotype and lymphocytes mount a cytotoxic T cell response to eliminate target cells, including preneoplastic cells. Thus, p21 concurrently induces proliferative arrest and immunosurveillance of cells under duress.

Development of a Clinically Relevant Reporter for Chimeric Antigen Receptor T-cell Expansion, Trafficking, and Toxicity

Although chimeric antigen receptor T (CART)-cell therapy has been successful in treating certain hematologic malignancies, wider adoption of CART-cell therapy is limited because of minimal activity in solid tumors and development of life-threatening toxicities, including cytokine release syndrome (CRS). There is a lack of a robust, clinically relevant imaging platform to monitor in vivo expansion and trafficking to tumor sites. To address this, we utilized the sodium iodide symporter (NIS) as a platform to image and track CART cells. We engineered CD19-directed and B-cell maturation antigen (BCMA)-directed CART cells to express NIS (NIS⁺CART19 and NIS⁺BCMA-CART, respectively) and tested the sensitivity of ¹⁸F-TFB-PET to detect trafficking and expansion in systemic and localized tumor models and in a CART-cell toxicity model. NIS⁺CART19 and NIS⁺BCMA-CART cells were generated through dual transduction with two vectors and demonstrated exclusive ¹²⁵I uptake in vitro. ¹⁸F-TFB-PET detected NIS⁺CART cells in vivo to a sensitivity level of 40,000 cells. ¹⁸F-TFB-PET confirmed NIS⁺BCMA-CART-cell trafficking to the tumor sites in localized and systemic tumor models. In a xenograft model for CART-cell toxicity, ¹⁸F-TFB-PET revealed significant systemic uptake, correlating with CART-cell in vivo expansion, cytokine production, and development of CRS-associated clinical symptoms. NIS provides a sensitive, clinically applicable platform for CART-cell imaging with PET scan. ¹⁸F-TFB-PET detected CART-cell trafficking to tumor sites and in vivo expansion, correlating with the development of clinical and laboratory markers of CRS. These studies demonstrate a noninvasive, clinically relevant method to assess CART-cell functions in vivo.

Prognostic evidence of LEF1 isoforms in childhood acute lymphoblastic leukemia

INTRODUCTION

The lymphoid enhancer factor 1 (LEF1) is a DNA-binding transcription factor that functions in the Wnt signaling pathway. Increased LEF1 activity is associated with progression of several types of cancer including leukemia. Here, we investigated LEF1 isoform expression and genomic variations in acute lymphoblastic leukemia (ALL).

METHODS

LEF1 isoform expression was evaluated by quantitative real-time PCR in 87 newly diagnosed childhood ALL patients and controls. Moreover, Western blot analysis was performed for detection of LEF1 expression and the hotspot region of LEF1 was screened by deep sequencing.

RESULTS

The LEF1 mRNA expression of B cell ALL patients was higher than the controls (LEF1-total P = .011, LEF1-long P = .026). Moreover, B-ALL samples showing higher total LEF1 expression had significantly shorter relapse-free survival (P = .008) and overall survival (P = .011). Although full-length LEF1 expression was similar to the controls in T-ALL, 50% (n = 15) of the ALL patients had increased full-length LEF1 protein expression. Imbalance between short- and full-length LEF1 isoforms may lead to cell survival in ALL. Beside the LEF1 activation, LEF1 gene variations were rarely observed in our cohort.

CONCLUSION

The results indicate that the Wnt pathway may have a pathogenic function in a group of ALL patients and high LEF1-total expression might be a marker for shorter relapse-free survival time in B cell ALL.

Leukemic extracellular vesicles induce chimeric antigen receptor T cell dysfunction in chronic lymphocytic leukemia

Chimeric antigen receptor (CAR) T cell therapy has yielded unprecedented outcomes in some patients with hematological malignancies; however, inhibition by the tumor microenvironment has prevented the broader success of CART cell therapy. We used chronic lymphocytic leukemia (CLL) as a model to investigate the interactions between the tumor microenvironment and CART cells. CLL is characterized by an immunosuppressive microenvironment, an abundance of systemic extracellular vesicles (EVs), and a relatively lower durable response rate to CART cell therapy. In this study, we characterized plasma EVs from untreated CLL patients and identified their leukemic cell origin. CLL-derived EVs were able to induce a state of CART cell dysfunction characterized by phenotypical, functional, and transcriptional changes of exhaustion. We demonstrate that, specifically, PD-L1+ CLL-derived EVs induce CART cell exhaustion. In conclusion, we identify an important mechanism of CART cell exhaustion induced by EVs from CLL patients.

In vivo CART cell imaging: Paving the way for success in CART cell therapy

Chimeric antigen receptor T (CART) cells are a promising immunotherapy that has induced dramatic anti-tumor responses in certain B cell malignancies. However, CART cell expansion and trafficking are often insufficient to yield long-term remissions, and serious toxicities can arise after CART cell administration. Visualizing CART cell expansion and trafficking in patients can detect an inadequate CART cell response or serve as an early warning for toxicity development, allowing CART cell treatment to be tailored accordingly to maximize therapeutic benefits. To this end, various imaging platforms are being developed to track CART cells in vivo, including nonspecific strategies to image activated T cells and reporter systems to specifically detect engineered T cells. Many of these platforms are clinically applicable and hold promise to provide valuable information and guide improved CART cell treatment.

DDRE-18. DEVELOPMENT OF EGFRvIII AND EGFR DIRECTED CHIMERIC ANTIGEN RECEPTOR T CELL THERAPY FOR THE TREATMENT OF GLIOBLASTOMA MULTIFORME

BACKGROUND

Chimeric antigen receptor T cell (CART) therapy has revolutionized the treatment landscape for hematological malignancies, its efficacy remains limited in solid tumors. EGFRvIII is a truncated version of the wild type EGFR in which deletion of exons 2–7 of the extracellular domain leads the variant (EGFRvIII) that is strongly antigenic and is mostly expressed on tumor cells. EGFR amplification (tEGFR) almost uniformly precedes the presence of EGFRvIII on tumor cells. The heterogeneity of surface receptor expression and immunosuppressive stromal microenvironment underscore the need to develop CART strategies to target multiple tumor antigens simultaneously.

METHODS

we generated tEGFR/EGFRvIII directed CAR construct by cloning a clinically relevant tEGFR and EGFRvIII specific scFv into a second generation CAR construct (41BB stimulated) in a third generation lentivirus backbone. This was used to transfect 293T cells and the generated lentivirus particles were used to transduce T cells and generate EGFRvIII/tEGFR CART cells. GBM primary patient derived cell lines were used in these experiments. These cells were passaged and maintained in patient derived xenograft models.

RESULTS

EGFRvIII/tEGFR directed CART cells exhibited potent antitumor activity against EGFRvIII/tEGFR + GBM cell lines: with 100% killing at 1.25:1, 2.5:1, 5:1 and 10:1 E:T ratio on multiple PDX cell lines with EGFRvIII expression and EGFR over-expression (greater than five copies of EGFR gene) at 24 hours of incubation. Conclusion: We demonstrate that targeting EGFRvIII and over-expressed EGFR with CART cells is feasible, efficacious and represents a promising therapeutic strategy to target GMB. Data from in vivo and combinatorial CART experiments will be reported at the meeting.

Pyoderma gangrenosum with thymoma and myasthenia gravis: A case report

Pyoderma gangrenosum (PG) is a rare, neutrophilic dermatosis which is characterized by painful, necrotic ulcer with violaceous border that heals with cribriform scar. Although the etiopathogenesis of PG is not known exactly, it can be triggered by many factors such as genetics, autoimmune, pathergy phenomenon, drugs, and paraneoplastic. It is frequently associated with autoimmune pathogenesis such as inflammatory bowel disease and rheumatologic disease. It can also be associated with hematological or solid organ malignancies, and then, it is called paraneoplastic PG. The association of PG with myasthenia gravis and thymoma has not been previously reported. In our case, these three diseases with a common paraneoplastic pathogenesis were seen together and the coexistence of the three diseases is rare. Treatment of PG should be decided according to the severity, spread of the lesions, concomitant disease, medical condition, and tolerance of the patient. The purpose of treatment is to control the lesions and related diseases for a long time with minimal side effects. Mycophenolate mofetil treatment was used safely and successfully for both generalized MG and PG in our case.

Recurrent WNT pathway alterations are frequent in relapsed small cell lung cancer

Nearly all patients with small cell lung cancer (SCLC) eventually relapse with chemoresistant disease. The molecular mechanisms driving chemoresistance in SCLC remain un-characterized. Here, we describe whole-exome sequencing of paired SCLC tumor samples procured at diagnosis and relapse from 12 patients, and unpaired relapse samples from 18 additional patients. Multiple somatic copy number alterations, including gains in ABCC1 and deletions in MYCL, MSH2, and MSH6, are identifiable in relapsed samples. Relapse samples also exhibit recurrent mutations and loss of heterozygosity in regulators of WNT signaling, including CHD8 and APC. Analysis of RNA-sequencing data shows enrichment for an ASCL1-low expression subtype and WNT activation in relapse samples. Activation of WNT signaling in chemosensitive human SCLC cell lines through APC knockdown induces chemoresistance. Additionally, in vitro-derived chemoresistant cell lines demonstrate increased WNT activity. Overall, our results suggest WNT signaling activation as a mechanism of chemoresistance in relapsed SCLC.

Ptosis Surgery Using Mersilene Mesh Suspensory Material

Frontalis suspension procedure using a Mersilene mesh sling was performed on 23 ptotic eyelids of 22 patients (age range 3 to 35 years) with poor or absent levator function. The surgical technique used was a modified Fox's method. The mean palpebral fissure height was 3.1 mm preoperatively and increased to 8.0 mm after the operation. No serious complication was seen postoperatively and during an average follow-up of 25 months. In one case with a cosmetically inadequate result, the upper third of the initially implanted Mersilene mesh was removed during reoperation and histological examination of the specimen revealed fibrovascular tissue invasion through the mesh fibres. Mersilene mesh appears to be an effective and safe alternative sling material for brow suspension surgery, giving good permanent results for cases in which autogenous fascia lata was inappropriate.

Changes in the Conjunctival Flora after Conjunctivodacryocystorhinostomy (CDCR): A Preliminary Report

Purpose

To describe changes in the conjunctival flora due to retrograde flow after conjunctivodacryocystorhinostomy (CDCR) with Jones’ tube implantation.

Methods

In 20 patients, one year after unilateral CDCR with Jones’ tube implantation and a functionally successful outcome, conjunctival and nasal mucosal specimens were taken from the operated side for bacteriological analyses and non-operated eye conjunctival specimens were simultaneously taken as the control group. The samples were cultivated in conventional media and also in hypertonic media in order to isolate L-forms of bacteria and to increase the isolation rate and sensitivity.

Results

Bacterial growth was detected in 16 operated (80%) and 11 non-operated eyes (55%) and 26 bacteria were isolated from nasal mucosa in 20 cases (isolation rate 100%). Bacteria isolated from the non-operated specimens were S. epidermidis (63.6%, seven cases), S. aureus (27.2%, three cases) and Corynebacterium sp. (9.0%, one case). Conjunctival cultures of the operated eyes yielded S. epidermidis in three (18.7%), S. aureus in six (37.5%), Corynebacterium sp. in two (12.5%) and other bacteria in five (31.3%). Nasal mucosal cultures contained S. epidermidis in nine cases (45%), S. aureus in eight (40%), Corynebacterium sp. in two (10%) and miscellaneous bacteria in seven cases (35%).

Conclusions

After CDCR the conjunctival flora of the eye undergoes differentiation and becomes similar to the nasal flora.

COMPARISON OF CARDIAC ARRHYTHMIA TYPES BETWEEN HYPERTHYROID PATIENTS WITH GRAVES' DISEASE AND TOXIC NODULAR GOITER

Purpose

Previous studies have demonstrated the relationship between hyperthyroidism and increased risk of cardiac arrhythmias. The most common causes of hyperthyroidism are Graves' disease (GD) and toxic nodular goiter (TNG). The aim of our study was to demonstrate if the underlying mechanism of hyperthyroidism, in other words autoimmunity, has an impact on the type of cardiac arrhythmias accompanying hyperthyroidism.

Method

Twenty patients with TNG and 16 patients with GD who had overt hyperthyroidism were included in the study. Age, sex, thyroid hormone levels, thyroid autoantibody positivity, thyroid ultrasonography and scintigraphy results were recorded. 24-hour Holter ECG monitoring was performed in all patients.

Results

Mean age was significantly higher in the TNG group compared to the GD group (62.9±11.5 vs. 48.9±8.6 years, p=0.001). Free T3 was significantly higher (7.87±3.90 vs. 5.21±1.53 pg/mL, p=0.033) in the GD group while free T4 and TSH levels were similar between the two groups. In 24-hour Holter ECG recordings nonsustained ventricular tachycardia (VT) rates were significantly higher in the GD group than in TNG group [18.75% (n=3/16) vs. 0% (n=0/20), respectively, (p=0.043)]. Paroxysmal atrial fibrillation (AF) rates were significantly higher in the TNG group compared to GD group [(30% (n=6/20) vs. 0% (n=0/16), respectively, (p=0.016)].

Conclusion

Although free T3 levels were lower, paroxysmal AF rates were found significantly higher in the TNG group which may be associated with significantly higher age of this group. On the other hand, higher rate of nonsustained VT in the GD group may be related to either significantly higher free T3 levels or autoimmunity.

MYC Drives Progression of Small Cell Lung Cancer to a Variant Neuroendocrine Subtype with Vulnerability to Aurora Kinase Inhibition

Loss of the tumor suppressors RB1 and TP53 and MYC amplification are frequent oncogenic events in small cell lung cancer (SCLC). We show that Myc expression cooperates with Rb1 and Trp53 loss in the mouse lung to promote aggressive, highly metastatic tumors, that are initially sensitive to chemotherapy followed by relapse, similar to human SCLC. Importantly, MYC drives a neuroendocrine-low "variant" subset of SCLC with high NEUROD1 expression corresponding to transcriptional profiles of human SCLC. Targeted drug screening reveals that SCLC with high MYC expression is vulnerable to Aurora kinase inhibition, which, combined with chemotherapy, strongly suppresses tumor progression and increases survival. These data identify molecular features for patient stratification and uncover a potential targeted treatment approach for MYC-driven SCLC.

Novel interactions between erythroblast macrophage protein and cell migration

Erythroblast macrophage protein is a novel protein known to mediate attachment of erythroid cells to macrophages to form erythroblastic islands in bone marrow during erythropoiesis. Emp-null macrophages are small with round morphologies, and lack cytoplasmic projections which imply immature structure. The role of Emp in macrophage development and function is not fully elucidated. Macrophages perform varied functions (e.g. homeostasis, erythropoiesis), and are implicated in numerous pathophysiological conditions such as cellular malignancy. The objective of the current study is to investigate the interaction of Emp with cytoskeletal- and cell migration-associated proteins involved in macrophage functions. A short hairpin RNA lentiviral system was use to down-regulate the expression of Emp in macrophage cells. A cell migration assay revealed that the relocation of macrophages was significantly inhibited when Emp expression was decreased. To further analyze changes in gene expression related to cell motility, PCR array was performed by down-regulating Emp expression. The results indicated that expression of mitogen-activated protein kinase 1 and thymoma viral proto-oncogene 1 were significantly higher when Emp was down-regulated. The results implicate Emp in abnormal cell motility, thus, warrants to assess its role in cancer where tumor cell motility is required for invasion and metastasis.

The effects of lauromacrogol on thyroid tissue in rabbits. Is this a safe option for the treatment of nodular thyroid disease?

AIM

The effects of lauromacrogol as a sclerosing agent were evaluated on rabbit thyroid tissue.

MATERIAL AND METHODS

Twelve rabbits were divided into two equal groups. Intra-thyroid injections of 0.1 ml lauromacrogol were administered in the study group and 0.1 ml physiologic serum in the control group. The blood levels of free T3, free T4, TSH, postoperative adhesions and histopathologic differences of the thyroid tissues were evaluated.

RESULTS

The values of serum free T3, free T4 and TSH levels did not differ significantly (p>0.05), but the free T3 levels were significantly different in the inter-group analysis (p=0.020). Postoperative macroscopic adhesion scores did not differ significantly (p>0.05). In the histopathologic evaluation, the inflammation and fibrosis scores were significantly higher in the study group (p=0.003).

DISCUSSION

In our study, we found two important outcomes. Firstly, tests of thyroid function were not significantly different between the control and study groups. This important finding suggests lauromacrogol can be safely used without the risk of hypothyroidism or hyperthyroidism. Secondly, the Erlich-Hunt Model histopathologic evaluation results revealed that inflammation and fibrosis were significantly increased in the study group. This finding shows lauromacrogol can be effectively used to treat thyroid nodules by means of fibrosis.

CONCLUSIONS

Lauromacrogol causes fibrosis in thyroid tissue without significant perithyroidal adhesion formation and functional differences. Treatment of nodular thyroid disease with lauromacrogol may be safe.

KEY WORDS

Lauromacrogol, Nodule, Thyroid.

The protective effect of the proteasome inhibitor bortezomib on the uterus of ovariectomized rats

Bortezomib (BORT) is an anti-tumour agent that inhibits proteasome, which is responsible for the degradation of many intracellular proteins. Although some side-effects and chemotherapeutic effects of BORT are known, there has not been enough research regarding its effects on different tissues of proteasome inhibition in the senile period (post-menopausal). The aim of this study was to investigate the safety of using BORT during the post-menopausal period. The post-menopausal effects of BORT were investigated on ovariectomized (OVX) Spraque-Dawley rats. The female rats were separated into three groups: control, ovariectomized (OVX), and OVX + BORT. OVX and OVX + BORT groups consisted of six rats in each. BORT was administered intraperitoneally in a dosage of 0.2 mg/kg two days a week for four weeks after OVX. The uteri of the rats were investigated using morphometrical, histopathological, and immunohistopathological methods. A striking atrophy in the endometrium and myometrium was observed due to an estrogen deficiency in the OVX group. The partial protective effect of BORT administration was observed morphometrically and histopathologically. In immunohistochemical research, cytoplasmic NF-KB activity was observed in the presence of proteasome inhibition in the endometrium. In light of these findings, the limited protective effects of post-menopausal BORT administration are worth mentioning.

A Deletion Mutation of the Connexin 26 (Gjb2) Gene in a Turkish Patient with Vohwinkel Syndrome

Vohwinkel syndrome (VS), also known as keratoderma hereditaria mutilans, is a rare keratinization genetic disorder characterized by palmoplantar keratoderma, skeletal dysmorphisms and varying degrees of sensorineural deafness. Its mode of inheritance is autosomal-dominant, with mutations in loricrin and connexin 26 (GJB2) genes that manifest during infancy and boceme more evident during adulthood. We herein report a case of VS in a 23-year-old female exhibiting sensorineural hearing loss, palmar keratoderma and homozygous deletion mutation delE120 (c.358-360delGAG) in the GJB2 gene. VS, is a rare genetic disorder, should be considered in patients with palmoplantar keratoderma and hearing loss and should be investigated connexin 26 (GJB2) gene mutation.

Effects of Diabetes on Post-Menopausal Rat Submandibular Glands: A Histopathological and Stereological Examination

OBJECTIVE

The menopause in elderly women is a physiological process where ovarian and uterine cycles end. Diabetes means higher blood glucose level that is a metabolic disease and has an increased incidence. The aim of the study was to examine the single or combined effects of menopause and diabetes that causes pathophysiological processes on submandibular gland on ovariectomy and diabetes induced rat models.

MATERIALS AND METHODS

Sprague Dawley twelve weeks old female (n=24) rats were divided randomly into four groups; Healthy control group (n=6), diabetic group (DM, n=6), ovariectomized group (OVX, n=6), post ovariectomy diabetes induced group (DM+OVX, n=6) individually. Histopathological, histochemical and stereological analyses were done in these groups.

RESULTS

Significant neutrophil cell infiltrations and myoepithelial cell proliferations, granular duct and seromucous acini damages and changes in the content of especially seromucous acini secretion in DM and/or OVX groups and distinctive interstitial and striated duct damages in post ovariectomy diabetes induced group were detected. Alterations ingranular ducts hypertrophic and in seromucous acini atrophic were determined in DM and/or OVX groups.

CONCLUSION

The results revealed the pathophysiological processes that lead to morphological and functional alterations on the cellular level in submandibular glands. The molecular mechanisms related with pathogenesis of diabetes and menopause need further investigation.

The apoptotic thanatotranscriptome associated with the liver of cadavers

Gene expression investigations are well-established components of ante mortem studies with broad applications ranging from elucidating basic mechanisms responsible for normal physiological processes to discovering therapeutic targets in pathophysiological conditions. However, gene expression studies and their application in the medico-legal field are still in their infancy. Therefore, the present study focuses on RNA using PCR array in the analysis of gene expression associated with tissues taken from actual criminal cases. RNA was extracted from the liver tissues of bodies with PMIs between 6 and 48 h. The results demonstrated that mRNA was stable up to 48 h postmortem. Further, as cell death is an indispensable and necessary part of the biological life cycle, apoptotic gene expression profiles were investigated. The gene expression related to the programmed cell death found in body tissues after death is defined as the apoptotic thanatotranscriptome (thanatos-, Greek for death). On comparison of control and decaying tissues, the results show that with time, pro-apoptotic genes such as caspases are up-regulated and the expression of genes responsible for anti-apoptosis such as BCL2 and BAG3 were down-regulated. Thus, this current work gives a unique perspective of the apoptotic thanatotranscriptome that is affected after death. Up to the present time, gene expression in bodies from criminal cases has not been reported in literature using PCR array techniques. Thus, this thanatotranscriptome study provides insight into postmortem gene activity with potential applications in medico-legal investigations.

Hepatoprotective effect of 17β-estradiol as antioxidant modulators against stress damage

BACKGROUND

Liver is one of the most important organs affected by exercise. According to the literature a few study to date has investigated the effects of estrogen supplementation on exercise-induced oxidative stress in liver tissue of rats.

OBJECTIVES

We aimed to investigate the effects of estrogen supplementation on oxidative stress markers in liver tissue of exercised rats.

MATERIALS AND METHODS

Male rats (n = 35) were divided as estrogen supplemented (n = 18) and non-supplemented groups (n = 17); these groups were further divided as rest and eccentric exercised groups. Eccentric exercise groups were further divided as rats killed after 1 hour and 48 hours of eccentric exercise. Estrogen (10 mg/kg) was administered subcutaneously for 30 days. Eccentric exercise was applied as treadmill run (15° downhill, 20 m/min) consisting of periods of "5 min" run and 2 min rest repeated 18 times. The rat liver was examined biochemically and histologically. Activities of GST, GSH-Px, CAT, SOD and MDA concentration were also measured spectrophotometrically.

RESULTS

Some disruptions were detected in experimental groups compared with the control group. Additionally, exercise training caused an increase in SOD and decrease in GSH-Px activities in some experimental groups. SOD activities increased significantly in group 3 (Estrogen (-), eccentric exercise (+) killed (after 1 h), compared with group 5 (Estrogen (-), eccentric exercise (+) killed (after 48 h). On the other hand, GSH-Px activities were also significantly decreased in groups 3, 4 and 5 compared with the control group. Leukocyte infiltration in liver increased after 48 hours compared with after 1 hour and estrogen supplementation was not able to prevent this infiltration.

CONCLUSIONS

Estrogen seemed to be not very effective to prevent eccentric exercise-induced liver damage.

Distinctive thanatomicrobiome signatures found in the blood and internal organs of humans

According to the Human Microbiome Project, 90% of the cells in a healthy adult body are microorganisms. What happens to these cells after human host death, defined here as the thanatomicrobiome (i.e., thanatos-, Greek defn., death), is not clear. To fill the void, we examined the thanatomicrobiome of the spleen, liver, brain, heart and blood of human cadavers. These organs are thought to be devoid of microorganisms in a healthy adult host. We report that the thanatomicrobiome was highly similar among organ tissues from the same cadaver but very different among the cadavers possibly due to differences in the elapsed time since death and/or environmental factors. Isolation of microbial DNA from cadavers is known to be a challenge. We compared the effectiveness of two methods by amplifying the 16S rRNA genes and sequencing the amplicons from four cadavers. Paired comparisons revealed that the conventional DNA extraction method (bead-beating in phenol/chloroform/bead-beating followed by ethanol precipitation) yielded more 16S rRNA amplicons (28 of 30 amplicons) than a second method (repeated cycles of heating/cooling followed by centrifugation to remove cellular debris) (19 of 30 amplicons). Shannon diversity index of the 16S rRNA genes revealed no significant difference by extraction method. The present report provides a proof of principle that the thanatomicrobiome may be an efficient biomarker to study postmortem transformations of cadavers.

Parathyroid allotransplantation in rabbits without cultivation

Permanent hypoparathyroidism is a serious clinical situation. Allotransplantation of the parathyroid cells is relatively new approach to treatment. Non-cultivated allotransplantation in rabbits is not tried before. In this research parathyroidectomy was performed in six female New Zealand white rabbits. After division of surgically removed tissues into two, cryopreservation after cell isolation was done. Non-cultivated cross allotransplantation was performed under immunosuppression. Serum calcium and phosphorus levels were observed 15 days and histopathological analyses of the transplanted parathyroid tissues were studied. Significant changes in serum calcium and phosphorus levels during the experiment were observed (p=0.001 for both). Calcium levels which were significantly dropped to 6.66±0.7 mg/dL after parathyroidectomy and progressively increased up to 15.98±1.25 mg/dL at the end of the experiment (p=0.004). Phosphorus levels which were increased to 9.38±0.63 mg/dL after parathyroidectomy and stabilized to 4.46±1.06 mg/dL at the end of the experiment (p=0.007). All allotransplanted parathyroid tissues showed normal tissue architecture without evidence of cellular rejection. In conclusion allotransplantation of the parathyroid tissues without cultivation may be considered as an alternative and safe approach for the treatment of permanent hypoparathyroidism.

Effects of melatonin on islet neogenesis and beta cell apoptosis in streptozotocin-induced diabetic rats: an immunohistochemical study

This investigation was carried out to explore the antidiabetic, antiapoptotic and neogenetic effects of melatonin (MLT) in streptozotocin-induced diabetic rats. Sixty-four male rats were assigned randomly to one of four groups for periods of 21 and 42 d as follows; i) control, ii) MLT, iii) diabetic (DM), and iv) DM + MLT. Immunohistochemical methods were used -with pancreatic tissue to determine the intensity of insulin, caspase-3 and Bcl-x(L) immune reactivities, and new islet formation. In untreated DM rats, BW loss, increased plasma glucose and MLT concentrations, as well as cytoplasmic degranulation and vacuolization were observed. We also observed a marked increase in the number of apoptotic caspase-3 positive cells and a few insulin- positive cells, but not antiapoptotic Bcl-x(L) positive cells. Observations in the DM + MLT-treated group revealed a high intensity of insulin- and antiapoptotic Bcl-x(L) immune reactivities at 21 and 42 d. Moreover, data indicated that MLT may cause beta cell proliferation and that new small islets originate from cells associated with ductal epithelium and from centroacinar cells by day 21. These data indicate that; i) MLT treatment may stimulate neogenesis in the pancreas of diabetic rats, and ii) MLT's antiapoptotic action may increase beta cell differentiation and caspase-3 inactivation or Bcl-x(L) activation.

Nigella sativa as a potential therapy for the treatment of lung injury caused by cecal ligation and puncture-induced sepsis model in rats

We investigated the potential protective effects of Nigella sativa (NS) on mortality, serum levels of proinflammatory cytokines, oxidative stress and histopathological changes in lung tissues, in cecal ligation and puncture (CLP)-induced sepsis model in rats. Sepsis induction by CLP, determination of serum cytokine levels by ELISA, spectrophotometric determination of oxidative stress parameters, and histological examination of lung tissues. The rat groups were: 1) CLP group, 2) sham group, 3) NS500-sham group, 4) NS125, 5) NS250, 6) NS500 groups. NS treatment significantly decreased proinflammatory cytokine levels in serum; LPO level, MPO activity, and pathological changes in lung tissues, in CLP-induced sepsis, while significantly increasing GSH levels and SOD activity in the lung tissue. NS treatment after CLP potentially reduced mortality and may exert effects through the reduction in tissue oxidative stress and serum cytokines. The histopathological changes were minimized in lung tissue by NS, under sepsis conditions. We can suggest that NS reverses the systemic inflammatory reaction to polymicrobial sepsis and thereby reduces multiple organ failure. It may be suggested that role of the NS ethanolic extract in preventing formation of CLP induced sepsis, is due to the anti-inflammatory and antioxidant effects of the different compounds of the black seeds.

Protective effect of Panax ginseng against serum biochemical changes and apoptosis in liver of rats treated with carbon tetrachloride (CCl4)

The purpose of this study was to investigate possible beneficial effects of Panax ginseng (PG) on carbon tetrachloride (CCl(4))-induced acute hepatotoxicity in rats. CCl(4) challenge elevated serum enzyme activities of liver and some biochemical parameters, but these effects were prevented by the pretreatment of rats with PG. Histologically, a great amount of mononuclear cells infiltration, necrotic cells and few fibroblasts were observed in liver of CCl(4) group. Also, CD68(+) and caspase-3 staining cells were diffused in both lobular and portal areas. However, PG pretreatment had a little influence on the number of caspase-3 immunopositive staining cells in the liver, but CD68(+) staining areas were significantly decreased in the PG+CCl(4) when compared to CCl(4) group. We conclude that PG treatment may play a protective role by enhancing liver enzyme activities and recovering biochemical parameters, and improving the changes in histological structure against CCl(4)-induced liver damages in rats.

Stereological and histological analysis of the developing rat heart

We studied with quantitative and microscopical methods the heart of rats divided into five age groups: embryos at the age of 11 days, fetuses at the age of 16 days and 20 days and also heart samples of 3-day-old pups and young adults (5 weeks of age) were used (n = 10 samples in each group). At the end of the study; heart samples were obtained from all animals. Stereological estimations were performed on heart volume, volume of heart lumen (ventricles and atria), volume of myocardium, numerical density of the myocyte nuclei and mean nuclear diameter of myocytes. Volumetric values and numerical data were estimated via Cavalieri method and physical dissector, respectively. In this study, histological examination was performed at light and electron microscopic levels. The numerical density of the myocyte nuclei increased from fetuses to young adults. Differences between embryos and fetuses, between fetuses and 3-day-old pups, and between 3-day-old pups and young adults were statistically significant. These results indicate that myogenesis continued in the rat myocardium during prenatal life and after birth.

Anencephalic fetuses can be an alternative for kidney transplantation: a stereological and histological investigation

In the study, stereological, histological, and anatomical techniques were used to investigate structural and morphometrical features of anencephalic and normal fetal kidneys. Twenty human fetal kidneys (5 male and 5 female anencephalic fetuses, and 5 male and 5 female normal fetuses) at gestational ages 30 to 35 weeks were examined. Our study used two basic research methods. One was conventional anatomical measurement at the macroscopic level, such as volume, length, weight, etc. The other consisted of conventional and modern microscopic techniques. The microscopic techniques were based on two research methods: histopathological examination at light microscopic level and stereological estimations, including mean kidney volumes, obtained by the Cavalieri method, and the total number and mean height of the glomeruli via the physical dissector method. There was no statistical difference between the two groups in terms of width, height, weight, and fluid replacement volumes. Microscopic quantitative assessment found no statistical differences either, in terms of the kidney volumes and the number and height of the glomeruli. Our findings suggest that kidneys from anencephalic infants may be a suitable alternative for renal transplantation.

Prognostic values of lesion volume and biochemical markers in ischemic and hemorrhagic stroke: a stereological and clinical study

PURPOSE

Our aim was to evaluate the relationship between lesion volume, serum level of biochemical markers, and clinical situation in ischemic and hemorrhagic stroke.

METHODS

MRI was obtained on 33 ischemic and 28 hemorrhagic strokes. The Cavalieri method was used to measure the volume. To evaluate neurological situation of the patients, we used the National Institutes of Health Stroke Scale (NIHSS) and Rankin Disability Scores at the first, third, seventh, and thirtieth days. We measured the level of leptin, high sensitivity C-reactive protein (hs-CRP), insulin, cortisol, fibrinogen, protein C, protein S, von Willebrand factor, D-dimer, Antitrombin III, and Factor VIII (F VIII) at the same time intervals.

RESULTS

In ischemic events, cortisol level at third and seventh days, and fibrinogen level at the first day were correlated with lesion volumes (r = 0.5, p = .02; r = 0.4, p = .02; r = 0.5, p = .005, respectively). In hemorrhagic events, only fibrinogen level was correlated with lesion volumes at third day (r = 0.6, p = .04). No significant differences were found among all these biochemical parameters, neurological situation (p > .05), and lesion volumes at all times.

CONCLUSION

In the prediction of stroke prognosis, lesion volume and all of the evaluated biochemical parameters are not deterministic factors.

Neurally-mediated sincope

Syncope is a syndrome characterized by a relatively sudden, temporary and self-terminating loss of consciousness; the causes may vary, but they have in common a temporary inadequacy of cerebral nutrient flow, usually due to a fall in systemic arterial pressure. However, while syncope is a common problem, it is only one explanation for episodic transient loss of consciousness (TLOC). Consequently, diagnostic evaluation should start with a broad consideration of real or seemingly real TLOC. Among those patients in whom TLOC is deemed to be due to ''true syncope'', the focus may then reasonably turn to assessing the various possible causes; in this regard, the neurally-mediated syncope syndromes are among the most frequently encountered. There are three common variations: vasovagal syncope (often termed the ''common'' faint), carotid sinus syndrome, and the so-called ''situational faints''. Defining whether the cause is due to a neurally-mediated reflex relies heavily on careful history taking and selected testing (e.g., tilt-test, carotid massage). These steps are important. Despite the fact that neurally-mediated faints are usually relatively benign from a mortality perspective, they are nevertheless only infrequently an isolated event; neurally-mediated syncope tends to recur, and physical injury resulting from falls or accidents, diminished quality-of-life, and possible restriction from employment or avocation are real concerns. Consequently, defining the specific form and developing an effective treatment strategy are crucial. In every case the goal should be to determine the cause of syncope with sufficient confidence to provide patients and family members with a reliable assessment of prognosis, recurrence risk, and treatment options.

The effects of high-fat diet on the renal structure and morphometric parametric of kidneys in rats

To characterize the kidney in a high-fat-induced obesity model, we examined the renal structure of adult Sprague-Dawley rats fed a control diet or a high-fat diet for 3 months. Ten adult female Sprague-Dawley rats were fed a diet consisting highly of fat (30%) for a period of 3 months. Ten control rats were maintained with standard rat chow. All animals were weighed every 10 days for 3 months. At the end of the experiment, the naso-anal length of the anaesthetized rats was measured to calculate body mass index, and subsequently whole kidneys of intracardially formalin-perfused animals were removed. Quantitative features of the kidney were analysed with the Cavalieri and physical dissector methods applied to serial paraffin sections. Kidney samples were also examined histologically. The body mass indices of the control and treatment groups were 4.528 +/- 0.242 and 5.876 +/- 0.318 kg m(-2), respectively. The difference between the body mass indices of the two groups was statistically significant (P < 0.01, Mann-Whitney U-test), suggesting that the animals fed with a high-fat diet may be overweight. Stereological examination of the kidneys revealed differences in kidney weight, total kidney volume, volume of cortex, medulla, glomeruli, proximal and distal tubules, and numerical density of glomeruli and glomerular height in the treatment group compared with the control group. Light microscopic investigation showed a dilatation in blood vessels and Bowman's space, mononuclear cell infiltration, degeneration in nephrons, including glomerulosclerosis and tubular defects, and an increase in the connective tissue in the kidneys in the treatment group. We concluded that a fatty diet is responsible for the rats' obesity and may lead to renal deformities as a result of histopathological changes such as dilatation, tubular defects, inflammation and connective tissue enlargement of the kidney.

The effect of perforator location on epigastric perforator flap survival: an experimental and stereological study in guinea pigs

One challenge most often seen in perforator-based flaps is the topographic relationship between the flap and its perforator, which determines flap design and pedicle length. Thirty female guinea pigs were used in this study. They were divided into four different groups including three experimental groups (n = 8), which were designed as central, lateral, and distal groups according to the perforator location, and one control group (n = 6). Flap survival and vessel density rates were assessed. There was no statistically significant difference ( P > 0.05) among either the surviving skin areas or the vascular density rates of the experimental groups, although all flaps were necrosed in the control group. We concluded that perforator flaps can safely be raised on the perforators located very distal or lateral to the flaps, as well as central classical location. Moreover, perforator flaps larger than suggested can safely be harvested in the same donor sites.