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Biomedical subjects

J J Ryan

Publications and source records attributed to J J Ryan.

At least 109 records · Page 6Linked to original sources
PubMed1993

Significance of autoantibodies to purified proteinase 3 in systemic vasculitis.

Proteinase 3 was purified from human neutrophils and used in ELISA to examine sera from 150 patients with systemic vasculitis. It was found to be the major target of autoantibodies in Wegener's granulomatosis, and anti-proteinase 3 antibodies were also found in some patients with microscopic polyarteritis. Anti-proteinase 3 antibodies were associated with a chronic relapsing course.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1993

Elimination of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) from human blood in the Yusho and Yu-Cheng rice oil poisonings.

The pharmacokinetics of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in humans was studied by monitoring the blood concentrations of individuals who ingested a contaminated rice oil in Japan (yusho) in 1968 and in Taiwan (yu-cheng) in 1979. Sixteen yusho patients were followed from 1982 to 1990 and three yu-cheng individuals from 1980 to 1989. From the three yu-cheng patients, blood lipid values for the two persistent toxic congeners, 2,3,4,7,8-pentachlorodibenzofuran (PnCDF) and 1,2,3,4,7,8-hexachlorodibenzofuran (HxCDF), varied from 50 micrograms/kg at first sampling to about 1 micrograms/kg at last sampling corresponding to half-lives for elimination (t1/2) of 2-21/2 years. The blood lipid values for the same PCDF congeners in yusho patients varied from 5 micrograms/kg down to 0.1 micrograms/kg. The calculated t1/2 were more variable with median values closer to 10 years. Planar PCBs #126 and #169 were present at lower concentrations than the PCDFs. For seven of the other PCB congeners, half-lives for elimination in the yu-cheng individuals varied from 1.2 up to 4.6 yr depending on the degree of chlorination. For the yusho patients, the elimination for the PCBs was longer. These results show that clearance of the toxic PCDFs and PCBs in humans is non-linear with faster elimination at higher exposure followed by slower decreases as background levels are approached. Such a clearance pattern can best be explained by a two compartment liver and fat pharmacokinetic model.

Adolescent↗
PubMed1993

Cell cycle analysis of p53-induced cell death in murine erythroleukemia cells.

A temperature-sensitive mutant of murine p53 (p53Val-135) was transfected by electroporation into murine erythroleukemia cells (DP16-1) lacking endogenous expression of p53. While the transfected cells grew normally in the presence of mutant p53 (37.5 degrees C), wild-type p53 (32.5 degrees C) was associated with a rapid loss of cell viability. Genomic DNA extracted at 32.5 degrees C was seen to be fragmented into a characteristic ladder consistent with cell death due to apoptosis. Following synchronization by density arrest, transfected cells released into G1 at 32.5 degrees C were found to lose viability more rapidly than did randomly growing cultures. Following release into G1, cells became irreversibly committed to cell death after 4 h at 32.5 degrees C. Commitment to cell death correlated with the first appearance of fragmented DNA. Synchronized cells allowed to pass out of G1 prior to being placed at 32.5 degrees C continued to cycle until subsequently arrested in G1; loss of viability occurred following G1 arrest. In contrast to cells in G1, cells cultured at 32.5 degrees C for prolonged periods during S phase and G2/M, and then returned to 37.5 degrees C, did not become committed to cell death. G1 arrest at 37.5 degrees C, utilizing either mimosine or isoleucine deprivation, does not lead to rapid cell death. Upon transfer to 32.5 degrees C, these G1 synchronized cell populations quickly lost viability. Cells that were kept density arrested at 32.5 degrees C (G0) lost viability at a much slower rate than did cells released into G1. Taken together, these results indicate that wild-type p53 induces cell death in murine erythroleukemia cells and that this effect occurs predominantly in the G1 phase of actively cycling cells.

Animals↗
PubMed1993

Dissociative symptoms in a substance abuse population.

OBJECTIVE: This study was intended to examine the extent of dissociative experiences that exist within a substance abuse population and to determine how demographic and clinical variables affect these experiences. METHOD: A total of 265 male veterans being treated on an inpatient substance abuse unit completed a standard test battery that included the MMPI-2, the Shipley-Hartford Institute of Living Scale, and the Dissociative Experiences Scale. Additional demographic and clinical information was obtained from the patients' medical records. RESULTS: Over 41% of the cohort had scores on the Dissociative Experiences Scale that suggested the need for further evaluation of a dissociative disorder. A stepwise multiple regression analysis revealed that level of psychological discomfort, IQ, and race accounted for more than 24% of the variance in Dissociative Experiences Scale scores. CONCLUSIONS: Substance abuse populations may need to be routinely screened for dissociative symptoms just as they are for depression and anxiety.

Adult↗
PubMed1993

Test-retest stability of the Satz-Mogel WAIS-R short form in a sample of normal persons 75 to 87 years of age.

The test-retest stability of the Sati-Mogel short form was evaluated in a sample of 61 persons 75 years and older. Means for age, education, and retest interval were 78.93 years (SD = 3.46), 9.74 years (SD = 1.91), and 64.92 days (SD = 26.84), respectively. Test-retest coefficients were.87,.70, and.89 for the Verbal, Performance, and Full Scales, respectively. Subtest stability ranged from.28 to.83. While the stability of the Verbal and Full Scales was adequate, it was unacceptable for the Performance Scale. Percent agreement for gain or loss between the complete WAIS-R and the Satz-Mogel short form was 80.0% for the Verbal Scale, 55.7% for the Performance Scale, and 67.2% for the Full Scale. The Satz-Mogel procedure reduces the stability of the Performance Scale to an unacceptable level in normal elderly persons.

Journal Article↗
PubMed1993

In vitro production of tumor necrosis factor by monocytes cultured from dialysis patients.

Cellular release of cytokines may be responsible for certain complications of extracorporeal dialysis including the increased susceptibility to infection found in dialysis patients. In order to study this further, we have evaluated the in vitro production of tumor necrosis factor (TNF) by peripheral blood monocytes (PBMC) to stimulation by lipopolysaccharide (LPS) from dialysis patients with end-stage renal failure (ESRF). The patients were subdivided into two groups according to the type of dialysis; those undergoing hemodialysis (HD) (N = 12) and those performing continuous ambulatory peritoneal dialysis (CAPD) (N = 9). Results were compared with those of controls taken from healthy laboratory staff (N = 7). The experiments show that the secretion of TNF by PBMC's in response to LPS is significantly augmented in patients undergoing HD when compared to those on CAPD (81.3 +/- 38.7 U/ml vs. 18.2 + 13.3 U/ml, mean +/- SD, P < 0.001); and controls (81.3 +/- 38.7 U/ml vs. 18.1 +/- 6.6 U/ml, P < 0.001). There was no significant difference between the CAPD group and controls. In vitro monocyte production of TNF fell following a single HD session (81.3 +/- 38.7 U/ml before HD and 50.5 +/- 28.7 U/ml after HD, P < 0.05). We conclude from this study that TNF release from PBMC's in vitro is augmented in patients with chronic renal failure receiving chronic HD but not in a similar group receiving CAPD. Interestingly, TNF release from monocytes collected immediately following a dialysis was suppressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Change of PCDF concentrations in the blood of Yusho patients in recent ten years].

The blood of 16 Yusho patients sampled from 1982 (14 years after the incident) to 1992 were analyzed for congeners of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) by high resolution gas chromatography-mass spectrometry and gas chromatography with electron capture detection, respectively. Biological half-lives of PCDFs and PCBs were estimated by following the change of blood concentrations of the Yusho patients in the equation of 1-compartment model. The biological half-lives of 2, 3, 4, 7, 8-penta-CDF and 1, 2, 3, 4, 7, 8-hexa-CDF in 8 individuals varied from 6.0 to 76 years with median 11.7 years and from 4.8 to 26.5 years with median 7.0 years, respectively. The half-lives of 1, 2, 3, 4, 6, 7, 8-hepta-CDF in 4 individuals varied from 2.1 to 15 years. Concentrations of PCBs in 13 individuals were estimated to be slowly decreased and increased with several years half-life in about half-and-half numbers.

Aged↗
PubMed1993

Breast reconstruction utilizing implants: a local experience and comparison of three techniques.

The breast reconstruction patient requires accurate information about the complications, failures, and additional surgeries associated with implant reconstruction. In this series of consecutive patients, we examine three methods of implant reconstruction: (1) immediate with a permanent implant/expander (86 patients/107 breasts), (2) delayed with a permanent implant/expander (57/73), and (3) delayed serial expansion with gel/saline (54/68). Implant/expander reconstructions had an equal interval to completion (immediate 118 days, delayed 127 days), a significant need for revisions (immediate 57 percent, delayed 30 percent), and a similar complication rate (10 percent) and failure rate (3.5 percent). The delayed serial expansion patients were completed with one operation 66 percent of the time, and only 9 percent required revisional surgery. The data obtained from the largest private health care provider in the state confirmed a significant difference (p = 0.003) in the need for revisional surgery between immediate and delayed reconstructions. The data showed immediate implant reconstructions to (1) be safe (low failure rate), (2) require more capsular intervention procedures, (3) have a greater expense, and (4) have good aesthetic results (90 percent Baker class I or II) because of revisional surgery. The immediate implant breast reconstruction patients are committed to their reconstruction and undergo revisional surgery to improve their aesthetic result. Delayed implant reconstruction patients are less likely to undergo further surgery to correct capsular deformities.

Adult↗
PubMed1992

Unusual combinations of verbal and performance IQs in normal and neurologically impaired elderly.

For the WAIS-R old age standardization sample, unusual Verbal-Performance IQ combinations were generated at the .05 and .01 levels of significance. In a preliminary attempt to determine the neurological significance of these unusual test score combinations, the standardization based values were compared to those of a small sample of elderly brain-injured subjects. The frequency of unusual IQ combinations was essentially the same for the normal and brain-damaged elderly. Unusual VIQ-PIQ combinations should not be considered pathognomonic of neurological impairment.

Aged↗
PubMed1992

Human mesangial cells synthesize interleukin 1 alpha but not interleukin 1 beta, interleukin 1 receptor antagonist, or tumour necrosis factor.

There is controversy over whether mesangial cells synthesize and release IL-1 and TNF, and many of the positive experiments were performed before specific reagents and molecular probes were available. Consequently we have stimulated human mesangial cells using protocols known to stimulate the synthesis of other cytokines. No mRNA for IL-1 beta or TNF could be detected in quiescent or proliferating mesangial cells irrespective of whether they had been exposed to cytokines or not. In contrast mRNA for IL-1 alpha was detected in cells stimulated with IL-1 beta 10 ng/ml or with TNF 500 ng/ml; IL-1 alpha was also detected in cell lysates from stimulated mesangial cells. We could not detect mRNA for IL-1 receptor antagonist in any of the cell preparations. These results suggest that mesangial cells are unlikely to be a major source of IL-1 beta or TNF.

Cells, Cultured↗
PubMed1992

Generalizability of two methods of estimating premorbid intelligence in the elderly.

Two methods for estimating premorbid WAIS-R IQ (Barona Reynolds & Chastain, 1984; Barona & Chastain, 1986) were compared in a sample of normal elderly and a sample of neurologically impaired persons. The normals consisted of 75 males with a mean age of 80.48 (SD = 4.57) years and the neurological group consisted of 20 males averaging 78.65 (SD = 5.62) years of age. For the normals, the percent of obtained IQs that fell within one standard error of estimate of the formula-estimated IQs demonstrated adequate agreement of both methods for the Full Scale IQ, but relatively poor prediction for the Performance Scale. The Verbal IQ was adequately predicted by the 1984 method, but not the 1986 procedure. As expected, both estimation procedures overestimated the obtained IQs of the brain-damaged subjects.

Journal Article↗
PubMed1992

Base rates of intersubtest scatter in the old age standardization sample of the WAIS-R.

The Wechsler Adult Intelligence Scale-Revised (WAIS-R) old-age standardization sample was analyzed to ascertain normal base rates of intersubtest scatter. The range and number of scaled scores that deviated by +/- 3 points from the mean were calculated for each subject on the Verbal, Performance, and Full Scale subtests. Mean ranges for the total sample were 4.4, 3.4, and 6.5, respectively. Ranges were larger for men than women; whites demonstrated more scatter than blacks. An increase in scatter emerged on the Verbal and Full Scales as one moved from the lowest to the highest education and IQ groups. Over 75% of individuals had two, one, or zero subtests that deviated significantly from their WAIS-R mean score. Finally, the scatter range for the elderly sample was compared to the original WAIS-R standardization sample.

Journal Article↗
PubMed1992

Persistent brominated and chlorinated dioxin blood levels in a chemist. 35 years after dioxin exposure.

This is the first report on occupational health hazards to dioxin chemists associated with laboratory exposure to 2,3,7,8-tetrabromodibenzodioxin (TBrDD), and further characterizes the human response to 2,3,7,8 tetrachlorodibenzodioxin (TCDD). In this case study the chemist was exposed on two separate occasions. In March 1956, after synthesizing 10 g of TBrDD, the chemist suffered from mild and transient chloracne of the neck and wrists; in September 1956, after synthesizing 16 g of TCDD, he suffered severe chloracne of the entire body, headaches, backache, and leg pain on exertion. His measured 2,3,7,8-TBrDD in 1991 was 625 parts per trillion (ppt) in whole blood lipid, 35 years after initial exposure and 18 ppt TCDD, an elevated level in comparison with the mean 2,3,7,8-TCDD level of 5 ppt in the US population. This is the first reported detection of a brominated dioxin in human tissue. The total halogenated dioxin body burden in September 1956 is estimated to have been between 13,005 ppt and 146,726 ppt. This amount can be considered to be, at least in this person, a strong chloracnegenic dose, and a dose causing human nervous system and muscular or circulatory system responses. This uptake demonstrates an occupational hazard to chemists and chemical workers, and the usefulness of human tissue dioxin measurements to document absorption.

Adult↗
PubMed1992

Factor analysis of the Chinese WAIS with persons who have mental retardation.

The Chinese revision of the WAIS (designated WAIS-RC) was factor analyzed for a sample of individuals with mental retardation. There were 55 Chinese subjects with a mean Full Scale IQ of 49.13 (SD = 16.46). Results indicated that a two-factor solution comprised of the familiar Verbal Comprehension and Perceptual Organization factors best described the data. Comparison of the Chinese structure with that of a low-IQ Canadian sample tested with the American WAIS-R revealed congruence coefficients of .97 and .98 for Verbal Comprehension and Perceptual Organization, respectively. These findings provide support for further cross-cultural research utilizing the latest editions of the American and Chinese Wechsler scales.

Adolescent↗
PubMed1992

c-myb effects on kinetic events during MEL cell differentiation.

During dimethylsulfoxide (DMSO)-induced differentiation of Friend mouse erythroleukemia (MEL) cells there is a biphasic fall in c-myb mRNA levels. We have previously shown that constitutive expression of c-myb blocks differentiation. To delineate more accurately the point at which Myb blocks differentiation, MEL cells were transfected with a human c-myb construct under the control of the beta-globin promoter and enhancers. In concert with endogenous DMSO-induced globin transcription during MEL cell differentiation, the beta-globin c-myb transcription unit of the transfected plasmid is activated after 3-5 days of culture in media containing DMSO. Here we describe c-myb-transformed MEL clones which undergo delayed expression of the exogenous c-myb following 3-5 days of culture in DMSO. In contrast to wild-type MEL cells, both clones failed to display phenotypic markers of differentiation and continued to proliferate for up to 10 days of culture. These data suggest that the late fall in c-myb levels may be required in order for differentiation to occur. Additionally, we suggest that constitutive expression of c-myb does not block early commitment events such as activation of histone Hl', subsequent chromatin condensation, and alteration of proliferation-related gene expression. Taken together, these results show that c-myb acts very late in the process of differentiation.

Animals↗
PubMed1991

Percentile rank conversion tables for WAIS-R IQs at six educational levels.

Estimated percentile ranks for Verbal, Performance, and Full Scale IQs are provided for the WAIS-R at six educational levels (N = 1,880). These tables are based on means and standard deviations from the standardization sample. Application of the tables is discussed, as are implications for clinical practice.

Educational Measurement↗