Effect of autophagy on multiple myeloma cell viability.

Because accumulation of potentially toxic malfolded protein may be extensive in immunoglobulin-producing multiple myeloma (MM) cells, we investigated the phenomenon of autophagy in myeloma, a physiologic process that can protect against malfolded protein under some circumstances. Autophagy in MM cell lines that express and secrete immunoglobulin and primary specimens was significantly increased by treatment with the endoplasmic reticulum stress-inducing agent thapsigargin, the mammalian target of rapamycin inhibitor rapamycin, and the proteasome inhibitor bortezomib. Inhibition of basal autophagy in these cell lines and primary cells by use of the inhibitors 3-methyladenine and chloroquine resulted in a cytotoxic effect that was associated with enhanced apoptosis.

IL-6-induced stimulation of c-myc translation in multiple myeloma cells is mediated by myc internal ribosome entry site function and the RNA-binding protein, hnRNP A1.

Prior work indicates that c-myc translation is up-regulated in multiple myeloma cells. To test a role for interleukin (IL)-6 in myc translation, we studied the IL-6-responsive ANBL-6 and IL-6-autocrine U266 cell lines as well as primary patient samples. IL-6 increased c-myc translation, which was resistant to rapamycin, indicating a mechanism independent of mammalian target of rapamycin (mTOR) and cap-dependent translation.

Efficacy of tacrolimus in rheumatoid arthritis patients who have been treated unsuccessfully with methotrexate: a six-month, double-blind, randomized, dose-ranging study.

Objective: To assess the efficacy, safety, and optimal dose of tacrolimus monotherapy in patients with rheumatoid arthritis (RA).

Methods: This phase II, randomized, double-blind, placebo-controlled monotherapy study was set in 12 community sites and 9 university-based sites. Two hundred sixty-eight patients with RA who were resistant to or intolerant of methotrexate (mean dose 15.

Expression of BAX in plasma cell dyscrasias.

Several studies demonstrate that the BCL-2 and BCL-XL antiapoptotic genes are variably expressed in plasma cells of patients with multiple myeloma (MM). However, the plasma cell expression of BAX protein, their major proapoptotic partner, has not been investigated. Our initial Western blot analysis of myeloma cell extracts also suggested patient variability in the expression of BAX, which was not altered by exposure to interleukin 6.

The interaction of nitric oxide (NO) with the yeast transcription factor Ace1: A model system for NO-protein thiol interactions with implications to metal metabolism.

Nitric oxide (NO) was found to inhibit the copper-dependent induction of the yeast CUP1 gene. This effect is attributable to an inhibition of the copper-responsive CUP1 transcriptional activator Ace1. A mechanism is proposed whereby the metal binding thiols of Ace1 are chemically modified via NO- and O(2)-dependent chemistry, thereby diminishing the ability of Ace1 to bind and respond to copper.

Everett Kinsey lecture. The elusive causes of keratoconus: a working hypothesis.

Purpose: Keratoconus is a diseasethat has been recognized clinically for many years. However, it is only more recently that a better understanding has been achieved in the area of keratoconus pathogenesis. The purpose of this paper is to summarize the completed research, review ongoing studies, and present a hypothesis for keratoconus pathology.

Analysis of gene expression in human bullous keratopathy corneas containing limiting amounts of RNA.

Purpose: To validate the use of polymerase chain reaction (PCR)-amplified full-length cDNA as a substitute for mRNA in nucleic acid array and gene expression analysis.

Methods: Total RNA was isolated from age-matched normal autopsy corneas and pseudophakic bullous keratopathy (PBK) corneas. Full-length cDNA was generated and PCR amplified using the Smart cDNA synthesis technology.

Enhanced expression of a transmembrane phosphotyrosine phosphatase (LAR) in keratoconus cultures and corneas.

The purpose of the study was to identify genes that are differentially expressed in normal versus keratoconus corneas. Total RNA isolated from corneal stromal cell cultures was reverse-transcribed and then amplified by the polymerase chain reaction (PCR) using defined, arbitrary primers. The products were displayed on polyacrylamide gels and bands that were differentially expressed were excised, re-amplified and subcloned.

BCL-X expression in multiple myeloma: possible indicator of chemoresistance.

Because murine myeloma plasma cells and normal human lymph node plasma cells express BCL-X, we evaluated BCL-X expression in malignant human plasma cells. BCL-X expression was detected in several human myeloma cell lines, as well as in CD38-sorted bone marrow cells obtained from some patients. Only the antiapoptotic long form of BCL-X (BCL-X-L), was detected.

Endovascular electrocoagulation: concept, technique, and experimental results.

Purpose: To evaluate the safety and efficacy of an embolotherapeutic technique that uses electrolytically detachable platinum coils and radio frequency (RF) energy to achieve rapid and distal occlusion of targeted vessels.

Methods: In swine, branches of the ascending cervical artery and the hepatic artery measuring 1.5 mm or less were subjected to endovascular electrocoagulation.

Abnormalities of the extracellular matrix in keratoconus corneas.

Purpose: To study alterations of the extracellular matrix (ECM) and basement membrane (BM) components in human keratoconus corneas.

Methods: Fifteen normal and 13 keratoconus corneas were characterized by immunofluorescence with antibodies to 23 ECM and BM components.

Results: Keratoconus staining patterns for posterior nonscarred regions and Descemet's membrane were normal.

Comparison of pediatric resident and faculty learning styles: implications for medical education.

This article compares resident and faculty learning strategies and styles and considers implications for teaching. The Kolb Learning Style Inventory was administered to 17 pediatric residents and 22 faculty in a pediatric department of an urban university-affiliated public medical center in 1991. Four scales--concrete experience (CE), reflective observation (RO), abstract conceptualization (AC), and active experimentation (AE)--are derived from self-ranking groups of words.

Cleavage of human corneal type VI collagen alpha 3 chain by matrix metalloproteinase-2.

The human cornea contains significant amounts of type VI collagen and matrix metalloproteinase-2 (MMP-2), but there has been no established relation between these two components. The objective of this study was to determine whether corneal type VI collagen was susceptible to digestion by MMP-2. Human corneas were frozen and then pulverized in liquid nitrogen.

Altered type VI collagen synthesis by keratoconus keratocytes in vitro.

Type VI collagen and gelatinase A are synthesized by human keratocytes in vitro. Keratoconus is a corneal disease that has increased gelatinase A activity. Normal keratocyte culture media analyzed by Western blotting with polyclonal antibody to type VI collagen showed a single 140 kDa band that increased in intensity after phorbol ester treatment.

Cleavage of structural components of mammalian vitreous by endogenous matrix metalloproteinase-2.

Our goal was to determine if the major endogenous vitreous matrix metalloproteinase (MMP-2) could digest known collagenous components of the vitreous body. Matrix metalloproteinase-2 and its associated inhibitors were isolated from porcine vitreous by affinity column chromatography. The inhibitors were inactivated by chemical modification with dithiothreitol and iodoacetamide.

Cleavage of structural components of mammalian vitreous by endogenous matrix metalloproteinase-2.

Our goal was to determine if the major endogenous vitreous matrix metalloproteinase (MMP-2) could digest known collagenous components of the vitreous body. Matrix metalloproteinase-2 and its associated inhibitors were isolated from porcine vitreous by affinity column chromatography. The inhibitors were inactivated by chemical modification with dithiothreitol and iodoacetamide.