Citations

Parthenogenesis is the biological phenomenon by which embryonic development is initiated without male contribution. Whereas parthenogenesis is a common mode of reproduction in lower organisms, the mammalian parthenote fails to produce a successful pregnancy. We herein describe in vitro parthenogenetic development of monkey ( Macaca fascicularis ) eggs to the blastocyst stage, and their use to create a pluripotent line of stem cells. These monkey stem cells (Cyno-1 cells) are positive for telomerase activity and are immunoreactive for alkaline phosphatase, octamer-binding transcription factor 4 (Oct-4), stage-specific embryonic antigen 4 (SSEA-4), tumor rejection antigen 1-60 (TRA 1-60), and tumor rejection antigen 1-81 (TRA 1-81) (traditional markers of human embryonic stem cells). They have a normal chromosome karyotype (40 + 2) and can be maintained in vitro in an undifferentiated state for extended periods of time. Cyno-1 cells can be differentiated in vitro into dopaminergic and serotonergic neurons, contractile cardiomyocyte-like cells, smooth muscle, ciliated epithelia, and adipocytes. When Cyno-1 cells were injected into severe combined immunodeficient mice, teratomas with derivatives from all three embryonic germ layers were obtained. When grown on fibronectin/laminin-coated plates and in neural progenitor medium, Cyno-1 cells assume a neural precursor phenotype (immunoreactive for nestin). However, these cells remain proliferative and express no functional ion channels. When transferred to differentiation conditions, the nestin-positive precursors assume neuronal and epithelial morphologies. Over time, these cells acquire electrophysiological characteristics of functional neurons (appearance of tetrodotoxin-sensitive, voltage-dependent sodium channels). These results suggest that stem cells derived from the parthenogenetically activated nonhuman primate egg provide a potential source for autologous cell therapy in the female and bypass the need for creating a competent embryo.

Background— Traditionally, increased pericardial thickness has been considered an essential diagnostic feature of constrictive pericarditis. Although constriction with a normal-thickness pericardium has been demonstrated clinically by noninvasive imaging, the details of clinicopathological correlates have not been described. Methods and Results— A total of 143 patients with proven constriction underwent pericardiectomy at Mayo Clinic between 1993 and 1999. Their baseline characteristics, operative data, and pathological specimens were reviewed retrospectively. The pericardium was of normal thickness (≤2 mm) in 26 patients (18%; group 1) and was thickened (>2 mm) in 117 (82%; group 2). The most common causes of constriction in group 1 included previous cardiac surgery, chest irradiation, previous infarction, and idiopathic disease. There was little difference in symptoms and findings on physical examination between the 2 groups. Microscopically, no patient had an entirely normal pericardium. Histopathological abnormalities in group 1 were mild and focal, including fibrosis, inflammation, calcification, fibrin deposition, and focal noncaseating granulomas. Pericardiectomy was equally effective in relieving symptoms regardless of the presence or absence of increased thickness. Conclusions— Pericardial thickness was not increased in 18% of patients with surgically proven constrictive pericarditis, although the histopathological appearance was focally abnormal in all cases. When clinical, echocardiographic, or invasive hemodynamic features indicate constriction in patients with heart failure, pericardiectomy should not be denied on the basis of normal thickness as demonstrated by noninvasive imaging.

AbstractThe optimal induction for older adults with acute myeloid leukemia (AML) is unknown. Several anthracyclines have been proposed, but the data remain equivocal. Additionally, few prospective trials of priming with hematopoietic growth factors to cycle leukemia cells prior to induction chemotherapy have been conducted. Three hundred and sixty-two older adults with previously untreated AML were randomized to either daunorubicin, idarubicin or mitoxantrone with a standard dose of cytarabine as induction therapy. In addition, 245 patients were also randomized to receive granulocyte-macrophage colony-stimulating factor (GM-CSF) or placebo beginning 2 days prior to induction chemotherapy and continuing until marrow aplasia. No difference was observed in the disease-free overall survival or in toxicity among patients receiving any of the 3 induction regimens or among those receiving growth factor or placebo for priming. However, the complete remission rate for the first 113 analyzable patients, who did not participate in the priming study and started induction therapy 3 to 5 days earlier than those who did, was significantly higher (50% versus 38%; P = .03). None of the anthracyclines is associated with improved outcome in older adults. Priming with hematopoietic growth factor did not improve response when compared with placebo. Furthermore, delaying induction therapy in older adults may lead to a lower complete remission rate.

Abstract Multiple myeloma (MM) is a progressive disease that is thought to result from multiple genetic insults to the precursor plasma cell that ultimately affords the tumor cell with proliferative potential despite its differentiated phenotype and resistance to undergoing apoptosis. Altered expression of antiapoptotic factors as well as growth factors have been described in a significant number of patients. However, the key regulatory elements that control myeloma development and progression remain largely undefined. Because of the knowledge that B-lymphocyte stimulator (BLyS), a tumor necrosis factor (TNF) family member shown to be critical for maintenance of normal B-cell development and homeostasis, promotes the survival of malignant B cells, we began a coordinated study of BLyS and its receptors in MM. All MM cells studied expressed one or more of 3 known receptors (B-cell maturation antigen [BCMA], transmembrane activator and CAML interactor [TACI], and B-cell activating factor receptor [BAFF-R]) for BLyS; however, the pattern of expression was variable. Additionally, we provide evidence that BLyS can modulate the proliferative capacity and survival of MM cells. Finally, we provide evidence that BLyS is expressed by MM cells and is present in the bone marrow of patients with MM. Expression of BCMA, TACI, and BAFF-R by MM taken together with the ability of BLyS to support MM cell growth and survival has exciting implications because they may be potential therapeutic targets.

Purpose: Intergroup Study 0114 was designed to study the effect of various chemotherapy regimens delivered after potentially curative surgical resection of T3, T4, and/or node-positive rectal cancer. A subset analysis was undertaken to investigate the prevalence and influence of salvage therapy among patients with recurrent disease. Patients and Methods: Adjuvant therapy consisted of two cycles of fluorouracil (FU)-based chemotherapy followed by pelvic irradiation with chemotherapy and two more cycles of chemotherapy after radiation therapy. A total of 1,792 patients were entered onto the study and 1,696 were assessable. After a median of 8.9 years of follow-up, 715 patients (42%) had disease recurrence, and an additional 10% died without evidence of disease. Five hundred patients with follow-up information available had a single organ or single site of first recurrence (73.5% of all recurrences). Results: A total of 171 patients (34% of those with a single organ or single site of recurrence) had a potentially curative resection of the metastatic or locally recurrent disease. Single-site first recurrences in the liver, lung, or pelvis occurred in 448 patients (90% of the single-site recurrences), with 159 (35%) of these undergoing surgical resection for attempted cure. Overall survival differed significantly between the resected and nonresected groups (P < .0001), with overall 5-year probabilities of .27 and .06, respectively. Controlling for worst performance status at the time of recurrence does not alter this relationship. Patients who underwent salvage surgery had significantly increased survival (P < .001) for each site. Conclusion: Attempted surgical salvage of rectal cancer recurrence is performed commonly in the United States. The chance of a long-term cure with such intervention is approximately 27%.

Until 1995, scientists held five widely accepted pillars of belief about estrogen action in the skeleton. Since then, a sea change in conventional wisdom has swept away these five beliefs. This lecture reviews data that have proved them wrong--or at least incomplete--and describes the new paradigms that have emerged to replace them. [Presentation] References 1. B. L. Riggs, S. Khosla, L. J. Melton III, Sex steroids and the construction and conservation of the adult skeleton. Endocr. Rev. 23 , 279-302 (2003). [Abstract] [Full Text]

During the past decade, the development of gene transfer technology provided a powerful and facile tool that afforded the genetic modification of vascular endothelial function. This development has coincided with molecular cloning and extensive accumulation of knowledge concerning the role of nitric oxide synthase isoforms in vascular homeostasis. Experimental evidence continues to accumulate that in vivo adenovirus-mediated gene transfer into the vessel wall is a very useful technique in studies designed to characterize function of a given gene or protein. In this review, we will use nitric oxide synthase gene transfer as a paradigm to illustrate how gene transfer technology can be used to address key issues in the vascular biology of endothelium.