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J Rogers

Publications and source records attributed to J Rogers.

At least 55 records · Page 3Linked to original sources
PubMed2001

The physical maps for sequencing human chromosomes 1, 6, 9, 10, 13, 20 and X.

We constructed maps for eight chromosomes (1, 6, 9, 10, 13, 20, X and (previously) 22), representing one-third of the genome, by building landmark maps, isolating bacterial clones and assembling contigs. By this approach, we could establish the long-range organization of the maps early in the project, and all contig extension, gap closure and problem-solving was simplified by containment within local regions. The maps currently represent more than 94% of the euchromatic (gene-containing) regions of these chromosomes in 176 contigs, and contain 96% of the chromosome-specific markers in the human gene map. By measuring the remaining gaps, we can assess chromosome length and coverage in sequenced clones.

Chromosomes, Human, Pair 1↗
PubMed2001

Individual variation in the growth of captive infant gorillas.

Serial anthropometric data were obtained during the first year of life of six nursery-reared infant gorillas in the Columbus (Ohio) Zoo. Two of the infants are likely to be monozygotic twins as determined by DNA analysis. Growth curves were fitted to serial measures of cephalo-thoracic-abdominal length, arm length, leg length, head circumference, upper arm circumference, and weight from each gorilla, to describe individual patterns of variation in skeletal growth and body composition. Growth in skeletal measures tended to be curvilinear to varying degrees over the first year of life. Body composition varied more than skeletal measures throughout the first year as a consequence of individual health status. Individual growth and body composition variations appear to reflect both genetic and environmental influences in this small sample of captive infant gorillas.

Animals↗
PubMed2001

Inflammatory repertoire of Alzheimer's disease and nondemented elderly microglia in vitro.

We have previously developed and characterized isolated microglia and astrocyte cultures from rapid (<4 h) brain autopsies of Alzheimer's disease (AD) and nondemented elderly control (ND) patients. In the present study, we evaluate the inflammatory repertoire of AD and ND microglia cultured from white matter (corpus callosum) and gray matter (superior frontal gyrus) with respect to three major proinflammatory cytokines, three chemokines, a classical pathway complement component, a scavenger cell growth factor, and a reactive nitrogen intermediate. Significant, dose-dependent increases in the production of pro-interleukin-1beta (pro-IL-1beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory peptide-1alpha (MIP-1alpha), IL-8, and macrophage colony-stimulating factor (M-CSF) were observed after exposure to pre-aggregated amyloid beta peptide (1-42) (Abeta1-42). Across constitutive and Abeta-stimulated conditions, secretion of complement component C1q, a reactive nitrogen intermediate, and M-CSF was significantly higher in AD compared with ND microglia. Taken together with previous in situ hybridization findings, these results demonstrate unequivocally that elderly human microglia provide a brain endogenous source for a wide range of inflammatory mediators.

Aged↗
PubMed2001

Superparamagnetic iron oxide MION as a contrast agent for sodium MRI in myocardial infarction.

An intravascular iron-based contrast agent was used as a sodium (23Na) MRI T2 relaxant in an effort to suppress the blood signal from the ventricular cavities in normal and infarcted canine myocardium in vivo. 23Na MRI signal decreases in blood were attributed to decreases in the fast (T2f) and slow (T2s) transverse relaxation components, which were quantified as a function of dose and MRI echo time (TE). In vivo 23Na MRI signal decreases up to 65% were noted in ventricular blood when imaging under dose and TE conditions of 10 mg/kg body weight and 5 ms, respectively. Contrast injection followed by subsequent 23Na MRI in canine myocardial infarction led to a clear delineation of the location of the injured tissue, as identified by postmortem triphenyltetrazolium chloride staining, and to an improvement in the contrast-to-noise ratio between the blood in the ventricular chamber and the infarcted tissue that was as high as 3.3-fold in the postcontrast images in comparison to the precontrast images.

Animals↗
PubMed2001

Involvement of microglial receptor for advanced glycation endproducts (RAGE) in Alzheimer's disease: identification of a cellular activation mechanism.

Receptor-mediated interactions with amyloid beta-peptide (Abeta) could be important in the evolution of the inflammatory processes and cellular dysfunction that are prominent in Alzheimer's disease (AD) pathology. One candidate receptor is the receptor for advanced glycation endproducts (RAGE), which can bind Abeta and transduce signals leading to cellular activation. Data are presented showing a potential mechanism for Abeta activation of microglia that could be mediated by RAGE and macrophage colony-stimulating factor (M-CSF). Using brain tissue from AD and nondemented (ND) individuals, RAGE expression was shown to be present on microglia and neurons of the hippocampus, entorhinal cortex, and superior frontal gyrus. The presence of increased numbers of RAGE-immunoreactive microglia in AD led us to further analyze RAGE-related properties of these cells cultured from AD and ND brains. Direct addition of Abeta(1-42) to the microglia increased their expression of M-CSF. This effect was significantly greater in microglia derived from AD brains compared to those from ND brains. Increased M-CSF secretion was also demonstrated using a cell culture model of plaques whereby microglia were cultured in wells containing focal deposits of immobilized Abeta(1-42). In each case, the Abeta stimulation of M-CSF secretion was significantly blocked by treatment of cultures with anti-RAGE F(ab')2. Treatment of microglia with anti-RAGE F(ab')2 also inhibited the chemotactic response of microglia toward Abeta(1-42). Finally, incubation of microglia with M-CSF and Abeta increased expression of RAGE mRNA. These microglia also expressed M-CSF receptor mRNA. These data suggest a positive feedback loop in which Abeta-RAGE-mediated microglial activation enhances expression of M-CSF and RAGE, possibly initiating an ascending spiral of cellular activation.

Aged↗
PubMed2001

Distinct isoforms of tau aggregated in neurons and glial cells in brains of patients with Pick's disease, corticobasal degeneration and progressive supranuclear palsy.

We investigated isoform composition of aggregated tau protein in brains with Pick's disease (PiD), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) by immunoblot analysis of sarkosyl-insoluble fractions of brain homogenates. We also examined the adjacent brain tissues immunohistochemically with a rabbit antibody, Ex10, which specifically recognizes exon 10 of tau. The Ex10 recognizes tau isoforms with four microtubule-binding repeats (4Rtau) but not those with three microtubule-binding repeats (3Rtau). Sarkosyl-insoluble tau from the brains of patients with CBD and PSP consisted of 4Rtau. Insoluble tau from the PiD brains contained both 3Rtau and 4Rtau, where 3Rtau predominated over 4Rtau. In brain tissues of CBD and PSP, Ex10 immunostained all neuronal and glial tau-positive structures. They included pre-tangles, astrocytic plaques, tuft-shaped astrocytes, and oligodendroglial coiled bodies. In PiD brains, astrocytic inclusions were also positive for 4Rtau. However, the majority of, if not all, Pick bodies and oligodendroglial tau inclusions were negative for 4Rtau. Such results suggest that, in neurons and oligodendroglia, tau isoforms involved in the pathological processes differ between CBD/PSP and PiD, and are thus disease specific. This contrasts with the astrocytic tau isoforms that accumulate similarly in all three disorders.

Astrocytes↗
PubMed2001

Cardiac arrest during surgery and ventilation in the prone position: a case report and systematic review.

We present a case report of successful resuscitation following cardiac arrest in a patient undergoing surgery in the prone position. A systematic review of the literature identified 22 further cases. Risk factors for intra-operative cardiac arrest in patients in the prone position include: cardiac abnormalities in patients undergoing major spinal surgery, hypovolaemia, air embolism, wound irrigation with hydrogen peroxide, poor positioning and occluded venous return. Cardiac arrest is also a risk in the increasing number of patients with acute respiratory distress syndrome ventilated in the prone position. Management of prone cardiac arrest may be improved by identification of high-risk patients, careful patient positioning, use of invasive monitoring and placement of self-adhesive defibrillator paddles. Suitable techniques for cardiopulmonary resuscitation including methods for chest compression, defibrillation and the management of air embolism are discussed.

Blood Loss, Surgical↗
PubMed2001

The effect of cytidine on the structure and function of an RNA ligase ribozyme.

A cytidine-free ribozyme with RNA ligase activity was obtained by in vitro evolution, starting from a pool of random-sequence RNAs that contained only guanosine, adenosine, and uridine. This ribozyme contains 74 nt and catalyzes formation of a 3',5'-phosphodiester linkage with a catalytic rate of 0.016 min(-1). The RNA adopts a simple secondary structure based on a three-way junction motif, with ligation occurring at the end of a stem region located several nucleotides away from the junction. Cytidine was introduced to the cytidine-free ribozyme in a combinatorial fashion and additional rounds of in vitro evolution were carried out to allow the molecule to adapt to this added component. The resulting cytidine-containing ribozyme formed a 3',5' linkage with a catalytic rate of 0.32 min(-1). The improved rate of the cytidine-containing ribozyme was the result of 12 mutations, including seven added cytidines, that remodeled the internal bulge loops located adjacent to the three-way junction and stabilized the peripheral stem regions.

Base Sequence↗
PubMed2001

Further improvements in laparoscopic donor nephrectomy: decreased pain and accelerated recovery.

Fear of postoperative pain is a disincentive to living donor kidney transplantation. Laparoscopic donor nephrectomy (LDN) was developed in part to dispel this disincentive. The dramatic increase in the number of laparoscopic donor nephrectomies performed at our institution has been in part due to the reduction in postoperative pain as compared to traditional, open donor nephrectomy. We sought to further diminish the pain associated with this surgical technique. The purpose of this study was to compare the efficacy of three different postoperative pain management regimens after LDN. All living kidney donors performed laparoscopically (n=43) between September 1998 and April 2000 were included for analysis. Primary endpoints included postoperative narcotic requirements and length of stay. Narcotic usage was converted to morphine equivalents (ME) for comparison purposes. Patients received one of three pain control regimens (group 1: oral and intravenous narcotics; group II: oral and intravenous narcotics and the On-Q pump delivering a continuous infusion of subfascial bupivicaine 0.5%; and group III: oral and intravenous narcotics and subfascial bupivicaine 0.5% injection). Postoperative intravenous and oral narcotic use as measured in morphine equivalents was significantly less in group III versus groups I and II (group III: 28.7 ME versus group I: 40.2 ME, group II: 44.8 ME; P<0.05). Postoperative length of stay was also shorter for group III (1.8 days) versus group I (2.5 days) and group II (2.9 days). LDN has been shown to be a viable alternative to traditional open donor nephrectomy for living kidney donation. We observed that the use of combined oral and intravenous narcotics alone is associated with greater postoperative narcotic use and increased length of stay compared to either a combined oral and intravenous narcotics plus continuous or single injection subfascial administration of bupivicaine. The progressive modification of our analgesic regimen has resulted in decreased postoperative oral and intravenous narcotic use and a reduction in the length of stay. We recommend subfascial infiltration with bupivicaine to the three laparoscopic sites and the pfannenstiel incision at the conclusion of the procedure to reduce postoperative pain. We believe this improvement in postoperative pain management will continue to make LDN even more appealing to the potential living kidney donor.

Adult↗
PubMed2001

Use of autologous radial artery for revascularization of hepatic artery thrombosis after orthotopic liver transplantation: case report and review of indications and options for urgent hepatic artery reconstruction.

Hepatic artery thrombosis (HAT) is the most common vascular complication after orthotopic liver transplantation (OLT) and has traditionally been managed with re-OLT. However, several reports have shown that urgent revascularization is frequently an effective means of graft salvage. This most often involves hepatic artery (HA) thrombectomy and thrombolysis, with reestablishment of arterial inflow through a donor iliac artery conduit based on the supraceliac or infrarenal aorta. We report a 46-year-old man who developed HAT 13 days after OLT after angiographic splenic artery embolization to reduce splenic artery steal. A suitable donor iliac artery was not available for arterial reconstruction and could not be obtained from neighboring transplant centers. The patient underwent urgent HA thrombectomy, intrahepatic arterial thrombolysis, and revascularization using an autologous radial artery (RA) conduit based on the supraceliac aorta. The patient is alive more than 1 year after revascularization, with normal liver function and documented flow in the arterial conduit by Doppler ultrasound and arteriography. He has not developed late biliary complications or adverse sequelae of RA harvest. Autologous RA can be safely and successfully used as an aortic-based arterial conduit in urgent revascularization of HAT after OLT. RA should be considered for use in HA revascularization if an adequate donor iliac artery is not available and other potential conduits are not usable or desirable. The availability of autologous RA expands the armamentarium of vascular conduits that can be used in HA revascularization and may help minimize re-OLT for otherwise potentially salvageable liver allografts.

Arterial Occlusive Diseases↗
PubMed2001

Long-range comparison of human and mouse SCL loci: localized regions of sensitivity to restriction endonucleases correspond precisely with peaks of conserved noncoding sequences.

Long-range comparative sequence analysis provides a powerful strategy for identifying conserved regulatory elements. The stem cell leukemia (SCL) gene encodes a bHLH transcription factor with a pivotal role in hemopoiesis and vasculogenesis, and it displays a highly conserved expression pattern. We present here a detailed sequence comparison of 193 kb of the human SCL locus to 234 kb of the mouse SCL locus. Four new genes have been identified together with an ancient mitochondrial insertion in the human locus. The SCL gene is flanked upstream by the SIL gene and downstream by the MAP17 gene in both species, but the gene order is not collinear downstream from MAP17. To facilitate rapid identification of candidate regulatory elements, we have developed a new sequence analysis tool (SynPlot) that automates the graphical display of large-scale sequence alignments. Unlike existing programs, SynPlot can display the locus features of more than one sequence, thereby indicating the position of homology peaks relative to the structure of all sequences in the alignment. In addition, high-resolution analysis of the chromatin structure of the mouse SCL gene permitted the accurate positioning of localized zones accessible to restriction endonucleases. Zones known to be associated with functional regulatory regions were found to correspond precisely with peaks of human/mouse homology, thus demonstrating that long-range human/mouse sequence comparisons allow accurate prediction of the extent of accessible DNA associated with active regulatory regions.

Animals↗
PubMed2001

Shape of the intercondylar notch of the human femur: a comparison of osteoarthritic and non-osteoarthritic bones from a skeletal sample.

OBJECTIVES: To compare objectively the shape of the intercondylar notch in human osteoarthritic and non-osteoarthritic femora. METHODS: A sample of 96 human femora from a large skeletal population were selected for study. These femora included subjects with evidence of late stage osteoarthritis (that is, with eburnation present) and subjects with no such evidence. The distal end of the femur, viewed axially, was recorded with a video camera, and digitised computer images were produced. The outline of the intercondylar notch was extracted and represented mathematically as two functions. A functional principal components analysis was used to identify important modes of shape variation. These variations in shape were compared between eburnated and non-eburnated femora. RESULTS: A statistically significant difference in the shape of the intercondylar notch was found between the two groups. The difference related mostly to the shape of the edge of the medial condyle: in the non-osteoarthritic group this tended to exhibit a concavity; in the osteoarthritic group it tended to be straight. CONCLUSIONS: This observed difference may be a predisposing factor to the development of osteoarthritis. The morphology of the intercondylar notch is related to the functioning of and possible damage to the cruciate ligaments, and damage to the cruciate ligaments is a known risk factor for osteoarthritis. Alternatively, this difference may be due to bony remodelling secondary to the onset of osteoarthritis, perhaps in response to altered biomechanics.

Adult↗
PubMed2001

Sodium-lithium countertransport activity is linked to chromosome 5 in baboons.

The genes involved in the regulation of cellular sodium transport characteristics, which are correlated with some forms of essential hypertension, have not yet been identified. We are studying the genes and environmental factors that affect red blood cell sodium-lithium countertransport (SLC) activity and intracellular sodium (ICNa) concentration in 634 baboons that comprise 11 pedigrees of 2 and 3 generations each. To detect and locate possible quantitative trait loci (QTLs) that affect SLC activity and ICNa concentration, we performed a genome screen by using a maximum likelihood-based variance-components linkage analysis program (SOLAR). SLC and ICNa phenotypes as well as genotypes on 281 microsatellite loci were available for all pedigreed animals. Both SLC and ICNa traits were highly heritable (residual heritability 0.593+/-0.083 [P<0.0001] and 0.739+/-0.082 [P<0.0001], respectively). We obtained evidence that a possible QTL for SLC activity is located on the baboon homologue of human chromosome 4 between D4S2456 and D4S2365 with a maximum multipoint lod score of 9.3 (P<10(-)(10)) near D4S1645. This QTL accounts for approximately two thirds of the total additive genetic variation in SLC activity in baboons. Although ICNa concentration was highly heritable, we found no evidence for linkage to a QTL with use of this methodology. Thus, we have evidence that a gene located on the baboon homologue of human chromosome 4 (baboon chromosome 5) affects cell sodium transport in baboons.

Animals↗
PubMed2001

Novel subcellular and molecular tools to study Ca(2+) transport mechanisms during the elusive moulting stages of crustaceans: flow cytometry and polyclonal antibodies.

Our understanding of calcium homeostasis during the crustacean moulting cycle derives from research on intermoult animals that has been extrapolated to other stages. In terms of transepithelial Ca(2+) flux, the more interesting stages are those surrounding ecdysis since crustaceans experience a sizeable negative calcium balance in immediate premoult and a significant positive calcium balance in immediate postmoult. These stages are elusive in the sense that larger species such as lobsters are rarely captured at this time, and smaller species such as blue crabs and crayfish are seldom synchronized in their moulting cycle. The reductionist approaches employed in cellular physiology, such as vesicle techniques, employ pooling of fresh tissues from many organisms. Examination of the elusive moulting stages requires more sensitive approaches that can utilize tissue from an individual crustacean to characterize Ca(2+) pumps (Sarco/Endoplasmic Reticulum Ca(2+)-ATPase, SERCA; Plasma Membrane Ca(2+)-ATPase, PMCA) and the Na(+)/Ca(2+) eXchanger (NCX). An emerging subcellular approach described in this paper is to use flow cytometry as a technique to monitor Ca(2+) uptake into Fluo-3-loaded membrane vesicles. This paper illustrates the utility of this technique for measuring ATP-dependent Ca(2+) uptake into hepatopancreatic basolateral membrane vesicles. Obstacles to progress in molecular studies have not been limited by synchronization of moulting since tissue can be snap-frozen and collected from many animals over time. Here, the problem has been the lack of specific antibodies that hybridize with the Ca(2+) transporters of interest so that they can be localized within epithelia. In this paper, we introduce polyclonal antibodies raised in rabbits against crayfish SERCA, PMCA and NCX. Immunocytochemistry of SERCA in muscle, PMCA in antennal gland and NCX in heart confirms the specificity of the antibodies.

Adenosine Triphosphate↗