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R J Graham

Publications and source records attributed to R J Graham.

17 recordsLinked to original sources
PubMed2001

An assessment of tissue harmonic versus fundamental imaging modes for echocardiographic measurements.

The study aimed to evaluate whether a significant difference exists between tissue harmonic imaging (THI) and fundamental imaging (FI) in routine quantitative echocardiographic assessment. We also examined the effects of THI on endocardial definition (ED). Fifty-eight unselected patients (29 men, 29 women; mean age 53 years) referred for transthoracic echocardiography were studied with use of both FI and THI modes. Two independent observers made M-mode measurements of the following: left atrium, aortic root, and left ventricular internal dimensions and wall thickness; they also measured left ventricular outflow tract diameter and left atrial area from 2-dimensional images. Endocardial definition was assessed with use of an arbitrary scoring system (0 = endocardium not visualized, 1 = endocardium visualized but suboptimally, 2 = endocardium well defined) and the American Society of Echocardiography 16-segment model. No significant difference existed between cardiac measurements derived from FI and THI. However, a highly significant improvement in ED occurred with THI (ED index 1.83 versus 1.70, P <.0001). This study suggests that no systematic differences exist in standard echocardiographic measurements between THI and FI, even in the setting of improved ED.

Adolescent↗
PubMed1999

Seven-color, homogeneous detection of six PCR products.

We describe an extension of the fluorogenic PCR 5'-nuclease assay, or "Taq-Man" assay. Sequence-specific probes consisted of a novel nonfluorescent quencher, nitrothiazole blue (NTB), at the 3' terminus and six different reporter dyes at the 5' terminus. The six reporters were 6-FAM, dR110, dR6G, dTMR, dROX and JAZ dyes. The seventh color was from aluminum phthalocyanine tetrasulfonate and was utilized as a "passive reference" to calibrate concentration variations. Our test system was a set of three single-nucleotide polymorphisms (SNPs). Each SNP system consisted of two primers and two sequence-specific probes, each labeled with a different reporter dye and NTB. Following PCR, the reactions were diluted with water and measured in a microcuvette on a luminescence spectrometer in synchronous scanning mode. In this method, both the excitation and emission wavelengths were scanned, with a fixed wavelength difference (delta gamma) between excitation and emission wavelengths. The spectral overlap in the set was evaluated by calculation of the condition number of the 7 x 7 matrix (dye fluorescence vs. wavelength). The small value of the condition number (1.5) proved that the cross-talk between the dyes was minimal. SNP analyses of known, synthetic target sequences and genomic DNA were plotted both as normalized, subtracted spectra and as data points in three separate dot plots.

DNA Probes↗
PubMed1998

Inflammation-associated lysyl oxidase protein expression in vivo, and modulation by FGF-2 plus IGF-1.

Lysyl oxidase is the extracellular enzyme that catalyzes oxidative deamination of peptidyl-lysine residues in elastin precursors, and lysine and hydroxylysine residues in collagen precursors to form peptidyl-aldehydes. These aldehydes then spontaneously condense to crosslink collagen and elastin and thereby allow the formation of a mature and functional extracellular matrix. In the present study, cryosections made from aseptic immune-induced periapical lesions experimentally generated in laboratory rats were examined by immunohistochemistry to investigate whether lysyl oxidase protein expression is altered in inflamed oral tissues. Periapical lesions are experimentally induced endodontic lesions of tooth roots. In addition, the effect of administration of a mixture of fibroblast growth factor (FGF)-2 and insulin-like growth factor (IGF)-1 into these lesions on lysyl oxidase expression was determined. Lysyl oxidase expression was found to be increased in non-mineralized connective tissue adjacent to inflamed lesions. Morphometric analyses indicated that maximum lysyl oxidase expression occurred at a discrete distance from the lesion not exceeding 350 microm from the inflammatory cells. Staining was associated with mesenchymal cells with a fibroblastic morphology. No lysyl oxidase staining was found near teeth where no lesion was induced. Application of a mixture of FGF-2 and IGF-1 resulted in a further twofold increase in lysyl oxidase expression. These results provide a new in vivo model to study lysyl oxidase regulation, and suggest that inflammatory cells may control lysyl oxidase expression in oral tissues, possibly by a mechanism involving secretion of cytokines and other factors, probably contributing to the regulation of extracellular matrix accumulation.

Animals↗
PubMed1998

Postoperative portable chest radiographs: optimum use in thoracic surgery.

PURPOSE: Daily portable chest radiographs are routinely ordered in many institutions after thoracic surgery. Our purpose was to assess the efficacy and cost of this practice and to determine the optimum use of postoperative x-ray studies. METHODS: A prospective review of all portable chest x-ray films after 100 consecutive elective thoracotomies (DRG 75) was conducted. Each x-ray study initiated a three-part survey. First, the surgeon listed whether the x-ray study was routine and the anticipated management had it not been available. The radiologist then interpreted and scored the x-ray study as follows: negative, expected findings; A, minor findings necessitating no intervention; B, minor findings necessitating intervention; or C, major findings necessitating intervention. Finally, the x-ray film and the interpretation were returned to the surgeon. Any interventions necessitated by the x-ray study were recorded. RESULTS: In 6 months, 99 patients underwent 82 pulmonary resections and 18 other major procedures. In the postoperative period, 769 portable chest x-ray studies were ordered, median five per patient (range 2 to 49). Of these, 731 (95%) were routine and 38 (5%), nonroutine. Severity scores were as follows: negative in 106 (13.8%), A in 558 (72.5%), B in 59 (7.7%), and C in 46 (6.0%). X-ray findings altered management in 43 of 769 studies (5.6%): in 33 routine (4.5%), in 10 nonroutine (26.3%), in 13 A (2.3%), in 22 B (37.3%), and in 8 C (17.4%). CONCLUSIONS: These results demonstrate that routine daily portable chest x-ray studies have a minimal impact on management. It is, in fact, nonroutine x-ray studies that more often alter management. Had routine portable chest x-ray studies, which cost $114 each in our institution, been limited to one immediately after the operation, only 133 such studies (100 routine and 33 nonroutine) would have been needed in the care of these patients. Elimination of 636 (82.7%) x-ray studies reduces the cost of care by $725 per patient ($286,000 annually). For major thoracic procedures, it is safe, efficacious, and cost effective to eliminate routine postoperative portable chest x-ray studies and order nonroutine portable studies only when clinically indicated.

Adult↗
PubMed1997

New energy transfer dyes for DNA sequencing.

We have synthesized a set of four energy transfer dyes and demonstrated their use in automated DNA sequencing. The donor dyes are the 5- or 6-carboxy isomers of 4'-aminomethylfluorescein and the acceptor dyes are a novel set of four 4,7-dichloro-substituted rhodamine dyes which have narrower emission spectra than the standard, unsubstituted rhodamines. A rigid amino acid linker, 4-aminomethylbenzoic acid, was used to separate the dyes. The brightness of each dye in an automated sequencing instrument equipped with a dual line argon ion laser (488 and 514 nm excitation) was 2-2.5 times greater than the standard dye-primers with a 2 times reduction in multicomponent noise. The overall improvement in signal-to-noise was 4- to 5-fold. The utility of the new dye set was demonstrated by sequencing of a BAC DNA with an 80 kb insert. Measurement of the extinction coefficients and the relative quantum yields of the dichlororhodamine components of the energy transfer dyes showed their values were reduced by 20-25% compared with the dichlororhodamine dyes alone.

Base Sequence↗
PubMed1984

Comparison of leucine aminopeptidase from human lens, beef lens and kidney, and hog lens and kidney.

Antisera specific for leucine aminopeptidase (LAP) were prepared. Using these antisera in immunodiffusion tests, the identity of LAP isolated from beef lens and kidney is demonstrated. The same pertains to hog lens and kidney LAP. As indicated by only partial fusion of the immunoprecipitates in immunodiffusion plates, leucine aminopeptidases isolated from hog and beef are antigenically similar but not identical. These tests also indicate substantial similarity between a component in human lens homogenates and bovine or hog LAP. Microcomplement fixation tests corroborate these observations and indicate that, under these conditions, LAP from beef lens and kidney, or hog lens and kidney, are indistinguishable. However, there is an approximate 8.5% amino acid sequence difference between beef and hog LAP. Microcomplement fixation tests with human lens homogenate also corroborate immunodiffusion results and indicate an approximate 19% amino acid sequence difference between beef and human LAP. These data establish that LAP is a species-specific enzyme and they indicate that it is not organ specific. Maximal complement fixation occurs at approximately 0.1 microgram antigen per tube in those assays in which pure aminopeptidases were tested. This permits standardization of the microcomplement fixation assay for LAP under these conditions. Maximal complement fixation occurs at 160-200 micrograms human lens homogenate per tube. Assuming that in this quantity of homogenate there is 0.1 microgram LAP, then it can be calculated that LAP comprises about 0.05% of the lens protein. This agrees closely with the percentage of LAP in hog and beef lenses. Thus, the reduced LAP activity reported for human lens tissue appears not to result from an absence of the enzyme but rather, may be due to diminished catalytic competency of the enzyme in aged human lens tissue (see Taylor and Juhngen , 1984). The unit evolutionary period, 4.7-5.8 X 10(6) years, indicates that LAP has been highly conserved during evolution.

Animals↗
PubMedDate not supplied

Congestive heart failure due to diastolic or systolic dysfunction. Frequency and patient characteristics in an ambulatory setting.

OBJECTIVE: To determine the age- and sex-specific frequencies and characteristics of patients with diastolic and systolic dysfunction heart failure. DESIGN: Retrospective medical record survey encompassing 1 year. SETTING: Community-based family practice office. PATIENTS: One hundred thirty-six patients who met the modified Framingham criteria for the diagnosis of congestive heart failure (CHF) and had a known left ventricular ejection fraction. Diastolic dysfunction was defined as an ejection fraction of 45% or greater and systolic dysfunction heart failure as an ejection fraction of less than 45%. MAIN OUTCOME MEASURES: Age- and sex-specific frequency; patient comorbid conditions; medications taken; and number of emergency department visits, hospitalizations, and deaths. RESULTS: The frequency of CHF increased with age for men and women (1.3% for patients 45-54 years old to 8.8% for patients > 75 years old). The distribution according to left ventricular ejection fraction and age varied according to sex. Women had later onset of CHF that was predominantly diastolic dysfunction heart failure. Men had proportionately more systolic dysfunction heart failure at all ages. Forty percent of all patients with CHF had diastolic heart failure, and these patients had fewer functional limitations (76% with New York Heart Association classes I and II), fewer hospitalizations for CHF, and a trend toward fewer deaths during the study year compared with patients with systolic dysfunction. CONCLUSIONS: Congestive heart failure is a heterogeneous condition in this family practice setting, and diastolic dysfunction heart failure occurs frequently. Further study of the natural history and treatment of diastolic dysfunction heart failure should be performed in the primary care setting.

Aged↗
PubMedDate not supplied

CT and MRI of aggressive osteoblastoma of thyroid cartilage.

We present a unique case of aggressive osteoblastoma arising from thyroid cartilage. A 52-year-old man presented with a 10 month history of neck discomfort but without frank pain. CT and MR examinations disclosed a well defined mass arising from the thyroid cartilage. This lesion had areas of coarse calcifications and a central area of lucency. The appearance suggested chondrosarcoma. Hemilaryngectomy was performed to remove the mass en bloc. Surgical pathology diagnosed aggressive osteoblastoma arising from thyroid cartilage.

Calcinosis↗