Author
Raymond J. MacDonald
Other affiliations: University of Pennsylvania, Howard Hughes Medical Institute, Michigan State University ...read more
Bio: Raymond J. MacDonald is an academic researcher from University of Texas Southwestern Medical Center. The author has contributed to research in topics: Gene expression & Pancreas. The author has an hindex of 56, co-authored 121 publications receiving 30650 citations. Previous affiliations of Raymond J. MacDonald include University of Pennsylvania & Howard Hughes Medical Institute.
Topics: Gene expression, Pancreas, Enhancer, Gene, Transcription factor
Papers published on a yearly basis
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TL;DR: In this article, the rat pancreas RNA was used as a source for the purification of alpha-amylase messenger ribonucleic acid (RBA) using 2-mercaptoethanol.
Abstract: Intact ribonucleic acid (RNA) has been prepared from tissues rich in ribonuclease such as the rat pancreas by efficient homogenization in a 4 M solution of the potent protein denaturant guanidinium thiocyanate plus 0.1 M 2-mercaptoethanol to break protein disulfide bonds. The RNA was isolated free of protein by ethanol precipitation or by sedimentation through cesium chloride. Rat pancreas RNA obtained by these means has been used as a source for the purification of alpha-amylase messenger ribonucleic acid.
19,805 citations
TL;DR: Bacterial clones containing inserted DNA sequences specific for α- Tubulin, β-tubulin,β-Actin and γ-actin have been constructed from mRNA of embryonic chick brain and are able to hybridize under stringent conditions to DNA of all vertebrates tested, as well as to sea urchin DNA, but not to yeast DNA.
1,650 citations
TL;DR: Rec recombination-based lineage tracing in vivo is used to show that PTF1a is expressed at these early stages in the progenitors of pancreatic ducts, exocrine and endocrine cells, rather than being an exocrine-specific gene as previously described.
Abstract: Pancreas development begins with the formation of buds at specific sites in the embryonic foregut endoderm. We used recombination-based lineage tracing in vivo to show that Ptf1a (also known as PTF1-p48) is expressed at these early stages in the progenitors of pancreatic ducts, exocrine and endocrine cells, rather than being an exocrine-specific gene as previously described. Moreover, inactivation of Ptf1a switches the character of pancreatic progenitors such that their progeny proliferate in and adopt the normal fates of duodenal epithelium, including its stem-cell compartment. Consistent with the proposal that Ptf1a supports the specification of precursors of all three pancreatic cell types, transgene-based expression of Pdx1, a gene essential to pancreas formation, from Ptf1a cis-regulatory sequences restores pancreas tissue to Pdx1-null mice that otherwise lack mature exocrine and endocrine cells because of an early arrest in organogenesis. These experiments provide evidence that Ptf1a expression is specifically connected to the acquisition of pancreatic fate by undifferentiated foregut endoderm.
995 citations
600 citations
TL;DR: Transfer of a 23 kb genomic DNA segment containing the rat elastase I gene to a foreign chromosomal location in the mouse can give rise to qualitatively and quantitatively normal expression.
298 citations
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TL;DR: A new method of total RNA isolation by a single extraction with an acid guanidinium thiocyanate-phenol-chloroform mixture is described, providing a pure preparation of undegraded RNA in high yield and can be completed within 4 h.
65,881 citations
TL;DR: In this article, the rat pancreas RNA was used as a source for the purification of alpha-amylase messenger ribonucleic acid (RBA) using 2-mercaptoethanol.
Abstract: Intact ribonucleic acid (RNA) has been prepared from tissues rich in ribonuclease such as the rat pancreas by efficient homogenization in a 4 M solution of the potent protein denaturant guanidinium thiocyanate plus 0.1 M 2-mercaptoethanol to break protein disulfide bonds. The RNA was isolated free of protein by ethanol precipitation or by sedimentation through cesium chloride. Rat pancreas RNA obtained by these means has been used as a source for the purification of alpha-amylase messenger ribonucleic acid.
19,805 citations
28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
TL;DR: The ob gene product may function as part of a signalling pathway from adipose tissue that acts to regulate the size of the body fat depot.
Abstract: The mechanisms that balance food intake and energy expenditure determine who will be obese and who will be lean. One of the molecules that regulates energy balance in the mouse is the obese (ob) gene. Mutation of ob results in profound obesity and type II diabetes as part of a syndrome that resembles morbid obesity in humans. The ob gene product may function as part of a signalling pathway from adipose tissue that acts to regulate the size of the body fat depot.
12,394 citations
TL;DR: A role for TNF-alpha in obesity and particularly in the insulin resistance and diabetes that often accompany obesity is indicated.
Abstract: Tumor necrosis factor-alpha (TNF-alpha) has been shown to have certain catabolic effects on fat cells and whole animals. An induction of TNF-alpha messenger RNA expression was observed in adipose tissue from four different rodent models of obesity and diabetes. TNF-alpha protein was also elevated locally and systemically. Neutralization of TNF-alpha in obese fa/fa rats caused a significant increase in the peripheral uptake of glucose in response to insulin. These results indicate a role for TNF-alpha in obesity and particularly in the insulin resistance and diabetes that often accompany obesity.
7,347 citations