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Biomedical subjects

K Ryan

Publications and source records attributed to K Ryan.

At least 37 records · Page 2Linked to original sources
PubMed1997

Relation between injections before 90-minute angiography and coronary patency: results of the thrombolysis in myocardial infarction 4 trial.

The current goal of thrombolytic therapy is to achieve both full (Thrombolysis in Myocardial Infarction [TIMI] grade 3) and early reperfusion. Newer reperfusion strategies may now achieve a high degree of reperfusion even earlier than the traditional 90-minute end point. To determine whether injections before 90 minutes affect this traditional end point, the relation between the number of injections before 90-minute angiography and patency was examined in the TIMI 4 trial. The number of injections before 90-minute angiography was no different between occluded arteries (TIMI grade 0/1 flow) (2.46 +/- 1.78; n = 94) and patent arteries (TIMI grade 2/3 flow) (2.71 +/- 2.42; n = 295) (p = 0.24). The incidence of any injections before 90 minutes was no different in patent versus closed arteries (80.6% [77/98] vs 72.4% [22/304]; p = 0.10). The number of injections before 90 minutes was insignificantly smaller in patients with TIMI grade 3 flow (2.53 +/- 2.53 [n = 184] vs 2.76 +/- 2.03 [n = 204]; p = 0.31), but the incidence of any injections before 90 minutes was significantly smaller in patients with TIMI grade 3 flow (68.8% [132/192] vs 79.5% [167/210]; p = 0.01). No relation was identified between the number of injections before 90-minute angiography and patency at this traditional time point. This observation justifies the judicious use of a limited number of "earlier snapshots" of the infarct-related artery before 90 minutes to ascertain just how rapidly newer thrombolytic regimens achieve patency. Patients with TIMI grade 3 flow had a slightly lower incidence of injections before 90 minutes, perhaps because they did not require as urgent a definition of coronary anatomy.

Aged↗
PubMed1997

Markers of vertebrate mesoderm induction.

Mesoderm formation is the first major differentiative event in vertebrate development. Many new mesoderm-specific genes have recently been described in the mouse, chick, frog and fish and belong to classes comprising T-domain genes, homeobox genes and those encoding secreted proteins. The T-domain genes have different but overlapping expression patterns and, in Xenopus, can ectopically activate nearly all other mesodermal genes. Several new homebox genes seem to mediate the ventralising activity of bone morphogenetic protein. New genes encoding secreted proteins induce dorsal mesoderm, in some cases by antagonizing ventralising factors.

Animals↗
PubMed1997

A comparison of the overall NRMP match results with the results for 19 specialties for senior U.S. medical students, 1996.

PURPOSE: To compare U.S. medical student Match results in 1996 for 19 categorical residency positions by specialty with those of the overall Match reported by the National Resident Matching Program (NRMP). METHOD: Data for the numbers of "active" senior U.S. student applicants (those who submitted rank lists), the numbers of U.S. seniors matched, and the numbers of unfilled positions for 19 specialties were obtained from a variety of sources. Chi-square analysis was performed to compare Match results for each independent specialty with the overall Match results. The level for statistical significant was set at p < .005. RESULTS: Eight specialties were identified as significantly more competitive than the overall Match process for both the percentage of U.S. seniors who successfully matched in that specialty and the ratio of unmatched U.S. senior applicants to unfilled categorical positions. Five specialties were identified as significantly less competitive for these two measures. Six specialties showed no significant difference in the percentages of U.S. students matching, but for three of these specialties there were more unmatched students than unfilled categorical positions. CONCLUSION: U.S. medical student Match results for categorical residency positions for different specialties vary significantly from the overall Match process. This information can be used in counseling senior medical students on their specialty selection and the residency application process.

Chi-Square Distribution↗
PubMed1997

The use of tobacco, alcohol and other drugs by young Aboriginal people in Albany, Western Australia.

This paper describes patterns of tobacco, alcohol and other drug use among Aboriginal people aged 8 to 17 years in the town of Albany, Western Australia. Of a total of 110 young Aboriginal people residing in the town at the time of the study, 105 were interviewed by two trained Aboriginal research assistants using interview schedules that included questions based on the national guidelines for the comparability of studies of drug use among young people. The most commonly used drugs were tobacco, alcohol and cannabis. Use of other substances was usually experimental, The majority (57 per cent) of this population had not used any drugs, 13 per cent made some use of alcohol and/or tobacco, 15 percent were polydrug users, and 15 per cent were frequent polydrug users. Use of drugs increased with age: 48 per cent of those aged 15 to 17 were frequent polydrug users. Tobacco consumption was greater and alcohol use less than that reported among Western Australian secondary school children of comparable age.

Adolescent↗
PubMed1997

The power of support groups: influence on infant feeding trends in New Zealand.

By outlining infant feeding trends and the essential characteristics of support groups, this paper reveals how important such groups and their development have been in shaping the history of infant feeding in twentieth-century New Zealand. The paper draws, in particular, on the histories, growth, and influence of the Royal New Zealand Plunket Society, Parents Centre New Zealand, and La Leche League New Zealand. It demonstrates the importance of such middle-class groups in changing practices and attitudes within society. In general, this paper is a call for recognition of the importance of lay support groups in the improvement of health outcomes.

Adult↗
PubMed1996

Eomesodermin, a key early gene in Xenopus mesoderm differentiation.

Eomesodermin (Eomes) is a novel Xenopus T-domain gene. In normal development, it is expressed in mesodermal cells in a ventral-to-dorsal gradient of increasing concentration. It reaches its peak expression 1-2 hr before any other known panmesodermal gene. It is strongly inducible by normal vegetal cells and by mesoderm-inducing factors. Ectopic expression of Eomes in animal caps induces the transcription of nearly all mesodermal genes in a concentration-dependent way. Overexpression of Eomes dorsalizes ventral mesoderm, inducing gsc and changing cell fate to muscle and notochord. Blocking the function of Eomes causes gastrulation arrest and defective mesoderm-dependent gene activation. We propose that Eomes fulfills an essential function in initiating mesoderm differentiation and in determining mesodermal cell fate.

Activins↗
PubMed1996

An experimental system for analyzing response to a morphogen gradient.

A recently described experimental system for analyzing the mode of action of a morphogen gradient involves the in situ hybridization of sectioned tissue constructs. In these constructs, a source of activin signaling induces the transcription of several mesodermal genes in blastula animal caps, according to the position of cells in a concentration gradient. New experiments show that activin-loaded beads emit a signal for only 2 hr and that the same cell can be induced to express different genes. We determine the position in the gradient and the time after the start of activin signaling at which early genes, including Mix1, Xpo, Xwnt8, Xchd, and Xlim1, are activated, relative to the previously tested genes Xbra and Xgsc.

Activins↗
PubMed1996

A randomized, double-blind comparison of single-dose and divided multiple-dose dolasetron for cisplatin-induced emesis.

PURPOSE: Intravenous dolasetron has been shown to be an effective antiemetic agent in patients receiving high-dose cisplatin-containing chemotherapy. Previous studies have suggested that 1.8 mg/kg is an optimal dose for achieving control of emesis and nausea. The objective of this study was to compare the efficacy and safety of a single intravenous (IV) dose of dolasetron with an equal divided multiple dose. METHODS: In this randomized, double-blind, parallel-group, multicenter study, the efficacy and safety of a single 1.8-mg/kg dose of dolasetron given 30 min prior to high-dose cisplatin ( > or = 80 mg/m2) chemotherapy was compared with the same total amount of dolasetron administered in three separate doses (0.6 mg/kg each) over a 12-h interval commencing 30 min prior to beginning chemotherapy and ending 11.5 h later. Antiemetic efficacy, safety, and tolerability were compared in 55 patients with various malignancies during the 24 h following the initiation of chemotherapy. The number of emetic episodes was the primary efficacy parameter. RESULTS: A single IV dose of dolasetron was generally more effective than a multiple-dose regimen in all measures of efficacy. There was a larger proportion of complete responders in the single-dose group compared with the multiple-dose group (48% vs 23%), although this difference did not reach statistical significance. Compared with the multiple-dose group, patients who received a single dose of dolasetron had a significantly (P = 0.034) longer median time to the first emetic episode (10.1 h vs > 24 h, respectively). Overall, 53% of patients had either a complete response or a major response to dolasetron, and only 40% of the total patient population received escape antiemetic medication in the 24 h after cisplatin administration. Except for headache, adverse events were similar with both regimens and were generally of mild or moderate intensity; no serious adverse events occurred. Neither dolasetron treatment regimen was associated with any clinically important events, trends in laboratory variables, or differences in safety profile. CONCLUSIONS: single-dose dolasetron was well tolerated and effectively controlled emesis and nausea in patients who received highly emetogenic, high-dose cisplatin chemotherapy. The greater antiemetic efficacy of a single prophylactic dose of dolasetron offers both convenience and potential cost savings, compared with a multiple-dose schedule of administration.

Aged↗
PubMed1996

An indelible lineage marker for Xenopus using a mutated green fluorescent protein.

We describe the use of a DNA construct (named GFP.RN3) encoding green fluorescent protein as a lineage marker for Xenopus embryos. This offers the following advantages over other lineage markers so far used in Xenopus. When injected as synthetic mRNA, its protein emits intense fluorescence in living embryos. It is non-toxic, and the fluorescence does not bleach when viewed under 480 nm light. It is surprisingly stable, being strongly visible up to the feeding tadpole stage (5 days), and in some tissues for several weeks after mRNA injection. We also describe a construct that encodes a blue fluorescent protein. We exemplify the use of this GFP.RN3 construct for marking the lineage of individual blastomeres at the 32- to 64-cell stage, and as a marker for single transplanted blastula cells. Both procedures have revealed that the descendants of one embryonic cell can contribute single muscle cells to nearly all segmental myotomes rather than predominantly to any one myotome. An independent aim of our work has been to follow the fate of cells in which an early regulatory gene has been temporarily overexpressed. For this purpose, we co-injected GFP.RN3 mRNA and mRNA for the early Xenopus gene Eomes, and found that a high concentration of Eomes results in ectopic muscle gene activation in only the injected cells. This marker may therefore be of general value in providing long term identification of those cells in which an early gene with ephemeral expression has been overexpressed.

Animals↗
PubMed1996

Mitigating engulfment: recovering from a first episode of psychosis.

1. Schizophrenia, and the challenge of coping with the ongoing stigma of mental illness, profoundly affects an individual's self-concept. 2. Individuals in the early phases of schizophrenia are at risk of becoming engulfed by their illness, such that all aspects of self become defined by the illness. 3. A group intervention enabled individuals to construct a positive self-concept through interacting with others, exploring the meaning of illness, developing an acceptable understanding of the illness, and developing diverse coping strategies.

Adaptation, Psychological↗
PubMed1995

Enhanced expression of an insulin growth factor-like binding protein (mac25) in senescent human mammary epithelial cells and induced expression with retinoic acid.

mac25, the subject of this report, was selected by the differential display of mRNA method in a search for genes overexpressed in senescent human mammary epithelial cells. mac25 had previously been cloned as a discrete gene, preferentially expressed in normal, leptomeningial cells compared with meningioma tumors. mac25 is another member of the insulin growth factor-binding protein (IGFBP) family. Insulin-like growth factors are potent mitogens for mammary epithelial cells, and the IGFBPs have been shown to modulate this mitogenic activity. We report here that mac25, unlike most IGFBPs, is down-regulated at the transcription level in mammary carcinoma cell lines, suggesting a tumor-suppressor role. The gene was mapped to chromosome 4q12. We found that mac25 accumulates in senescent cells and is up-regulated in normal, growing mammary epithelial cells by all-trans-retinoic acid or the synthetic retinoid fenretinide. These findings suggest that mac25 may be a downstream effector of retinoid chemoprevention in breast epithelial cells and that its tumor-suppressive role may involve a senescence pathway.

Amino Acid Sequence↗
PubMed1995

Predicting diabetic control from competence, adherence, adjustment, and psychopathology.

OBJECTIVE: To determine what psychological and behavioral factors were most predictive of diabetic control. METHOD: Seventy-nine youths with diabetes were assessed cross-sectionally, using youths' reports of self-esteem, anxiety, and attitudes about diabetes, and parents' reports of competence and psychopathology (from the Child Behavior Checklist) and diabetic adherence as independent variables. Glycosylated hemoglobin A1c was the dependent variable, reflecting diabetic control. After the effects of several background variables were partialed out, a principal-components analysis grouped the substantive variables into three larger components. RESULTS: Among the background variables, duration of illness and family size significantly predicted diabetic control. Among substantive components, Competence/Adherence (including Total Competence, dietary compliance, and frequency of blood glucose checks) was highly predictive of diabetic control, primarily due to the effect of Total Competence. Adjustment (including self-esteem, anxiety levels, and attitudes about diabetes) and Psychopathology were less predictive. A model was constructed showing the relationships between these predictive components and diabetic control. CONCLUSIONS: In this generally well-adjusted sample, that Total Competence, more than other measures, predicted diabetic control suggests it could be used by clinicians to anticipate diabetic youths at risk.

Adolescent↗
PubMed1995

Victims of violence in Fiji.

OBJECTIVE: The aim of the paper is to examine the statistics for violence performed by self or others in Fiji during the period 1969-1989 in the following sub-classifications: (1) fatal vs non-fatal; (2) Fijian vs Indian; and (3) male vs female. METHOD: Crude rates per 100,000 were determined and the data sets were statistically examined. RESULTS: (1) Violence by self, which includes suicide and non-fatal injury by self, has significantly increased; (2) Indian violence by self has increased in both males and females; (3) suicide is 4 times more common than homicide, whereas non-fatal injury by others is 4 times more common than non-fatal injury by self; (4) non-fatal injury by self is 8 times more common than suicide, whereas non-fatal injury by others is over 100 times more common than homicide; (5) Indian violence by self is 6 times more common than Fijian violence by self, whereas Fijians experience violence by others 2.5 times more commonly than Indians; (6) female violence by self is 1.5 times more common than male violence by self, whereas male violence by others is 3 times more common than female violence by others; (7) the rates of suicide and homicide are low by international standards; and (8) Fijian violence by self is particularly low, but consistent with the low suicide rate of the indigenous populations in surrounding geographical regions. CONCLUSION: Our findings suggest that racial differences in violence are likely to be due to cultural factors.

Cause of Death↗