Pim1 Kinase Overexpression Enhances ckit Cardiac Stem Cell Cardiac Repair Following Myocardial Infarction in Swine.

Background: Pim1 kinase plays an important role in cell division, survival, and commitment of precursor cells towards a myocardial lineage, and overexpression of Pim1 in ckit cardiac stem cells (CSCs) enhances their cardioreparative properties.

Objectives: The authors sought to validate the effect of Pim1-modified CSCs in a translationally relevant large animal preclinical model of myocardial infarction (MI).

Methods: Human cardiac stem cells (hCSCs, n = 10), hckit CSCs overexpressing Pim1 (Pim1; n = 9), or placebo (n = 10) were delivered by intramyocardial injection to immunosuppressed Yorkshire swine (n = 29) 2 weeks after MI.

Synergistic Effects of Combined Cell Therapy for Chronic Ischemic Cardiomyopathy.

Background: Both bone marrow-derived mesenchymal stem cells (MSCs) and c-kit(+) cardiac stem cells (CSCs) improve left ventricular remodeling in porcine models and clinical trials. Using xenogeneic (human) cells in immunosuppressed animals with acute ischemic heart disease, we previously showed that these 2 cell types act synergistically.

Objectives: To more accurately model clinical applications for heart failure, this study tested whether the combination of autologous MSCs and CSCs produce greater improvement in cardiac performance than MSCs alone in a nonimmunosuppressed porcine model of chronic ischemic cardiomyopathy.

Growth hormone-releasing hormone agonists reduce myocardial infarct scar in swine with subacute ischemic cardiomyopathy.

Background: Growth hormone-releasing hormone agonists (GHRH-As) stimulate cardiac repair following myocardial infarction (MI) in rats through the activation of the GHRH signaling pathway within the heart. We tested the hypothesis that the administration of GHRH-As prevents ventricular remodeling in a swine subacute MI model.

Methods And Results: Twelve female Yorkshire swine (25 to 30 kg) underwent transient occlusion of the left anterior descending coronary artery (MI).

Brief formalin fixation and rapid tissue processing do not affect the sensitivity of ER immunohistochemistry of breast core biopsies.

Objectives: Recent studies have questioned the supporting evidence for the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines of the 8-hour minimum fixation time required for estrogen receptor immunohistochemistry (ER-IHC) assays in breast cancer.

Methods: We investigated whether brief formalin fixation together with rapid tissue processing affects the sensitivity of ER in core breast biopsies. Five core samples each from 22 mastectomy specimens were collected and fixed in 10% formalin for periods ranging from 30 minutes to 1 week.

Enhanced effect of combining human cardiac stem cells and bone marrow mesenchymal stem cells to reduce infarct size and to restore cardiac function after myocardial infarction.

Background: Because mesenchymal stem cells (MSCs) induce proliferation and differentiation of c-kit(+) cardiac stem cells (CSCs) in vivo and in vitro, we hypothesized that combining human (h) MSCs with c-kit(+) hCSCs produces greater infarct size reduction compared with either cell administered alone after myocardial infarction (MI).

Methods And Results: Yorkshire swine underwent balloon occlusion of the left anterior descending coronary artery followed by reperfusion and were immunosuppressed after MI with cyclosporine and methylprednisolone. Intramyocardial combination hCSCs/hMSCs (1 million cells/200 million cells, n=5), hCSCs alone (1 million cells, n=5), hMSCs alone (200 million cells, n=5), or placebo (phosphate-buffered saline; n=5) was injected into the infarct border zones at 14 days after MI.

FGF23 induces left ventricular hypertrophy.

Chronic kidney disease (CKD) is a public health epidemic that increases risk of death due to cardiovascular disease. Left ventricular hypertrophy (LVH) is an important mechanism of cardiovascular disease in individuals with CKD. Elevated levels of FGF23 have been linked to greater risks of LVH and mortality in patients with CKD, but whether these risks represent causal effects of FGF23 is unknown.

Late onset sporadic dilated cardiomyopathy caused by a cardiac troponin T mutation.

Mutations in TNNT2, encoding cardiac troponin T, commonly shows early onset, aggressive dilated cardiomyopathy (DCM). This observation may influence the decision of whether to undertake clinical genetic testing for TNNT2 in later onset DCM. Further, the trigger for late onset DCM remains enigmatic.

Rapid-response, molecular-friendly surgical pathology: a radical departure from the century-old routine practice.

Background: Currently, surgeons have to wait for at least 1 day to receive the pathology report of a biopsy or other surgical excision. This delay is mandated by the overnight tissue-processing methods that have been in use for more than a century. Patient anxiety and delay in treatment are consequences of this practice.

Preservation of biomolecules in breast cancer tissue by a formalin-free histology system.

Background: The potential problems associated with the use of formalin in histology, such as health hazards, degradation of RNA and cross-linking of proteins are well recognized. We describe the utilization of a formalin-free fixation and processing system for tissue detection of two important biopredictors in breast cancer - estrogen receptor and HER2 - at the RNA and protein levels.

Methods: Parallel sections of 62 cases of breast cancer were fixed in an alcohol-based molecular fixative and in formalin.

Methodology for preservation of high molecular-weight RNA in paraffin-embedded tissue: application for laser-capture microdissection.

Laser-capture microdissection techniques have enhanced the ability to perform molecular studies of pure-cell populations. Although many technical factors affect the outcome of the procedure, none is more critical than the appropriate handling of the tissue. Because extraction of intact RNA from paraffin-embedded tissue is a difficult and inconsistent process, frozen sections with their attendant problems are used for this purpose.

Immunohistochemistry of estrogen and progesterone receptors reconsidered: experience with 5,993 breast cancers.

Paraffin sections or fine-needle aspiration smears from 5,993 cases of invasive mammary carcinomas were assessed immunohistochemically for estrogen receptor (ER; 1D5) and progesterone receptor (PR; 636) expression. Staining pattern and intensity were correlated with histologic subtypes and nuclear grades of tumors. Positive nuclear staining for ER and PR was observed in 75% and 55% of invasive carcinomas, respectively.

Experience with an automated microwave-assisted rapid tissue processing method: validation of histologic quality and impact on the timeliness of diagnostic surgical pathology.

We studied the effect of a fully automated microwave-assisted rapid tissue processor (RTP) on histologic examination and on the turnaround time for surgical pathology reports. A quality assurance program reviewed the histologic sections obtained by the rapid processing method for the last 3 calendar years. In addition, the histologic results from this method were compared blindly with those obtained from the conventional overnight tissue processing (CTP) method by 9 pathologists with different levels of experience.

A tissue fixative that protects macromolecules (DNA, RNA, and protein) and histomorphology in clinical samples.

Preservation of macromolecules (DNA, RNA, and proteins) in tissue is traditionally achieved by immediate freezing of the sample. Although isolation of PCR-able RNA has been reported from formalin-fixed, paraffin-embedded tissues, the process has not been shown to be reproducible because high molecular weight RNA is usually degraded. We investigated the potential value of a new universal molecular fixative (UMFIX, Sakura Finetek USA, Inc.

Continuous-specimen-flow, high-throughput, 1-hour tissue processing. A system for rapid diagnostic tissue preparation.

Context: Current conventional tissue-processing methods employ fixation of tissues with neutral buffered formalin, dehydration with alcohol, and clearing with xylene before paraffin impregnation. Because the time required for this procedure is usually 8 hours or longer, it is customary to process tissues in automated instruments throughout the night. Although this time-honored method continues to serve histology laboratories well, it has a number of shortcomings, such as a 1-day delay of diagnosis, the need to batch specimens, the relatively large volumes and toxicity of reagents used, and the extent of RNA degradation.