Search PubMed⌕ Search

Biomedical subjects

J K Dunn

Publications and source records attributed to J K Dunn.

At least 55 records · Page 3Linked to original sources
PubMed1993

Medical skills and knowledge. How necessary are they for psychiatric nurses?

1. Today's psychiatric population presents with a higher acuity and complexity of problems. Concomitant medical diagnoses may add to the psychiatric nurse's uneasiness with medical-surgical skills and knowledge. 2. A needs assessment survey of nurses' medical-surgical skills and knowledge was conducted at a private psychiatric facility. Of the 163 surveys distributed, 55 were returned (response rate = 33.74%). The greatest number of skill requests (30.56%) were for assessment skills, mainly general physical assessment. 3. To survive as a specialty, psychiatric nursing must include physical as well as psychologic assessments; psychiatric nurses must reintegrate a medical knowledge base while maintaining a balance with the psychodynamic aspects of care.

Clinical Competence↗
PubMed1992

Correlation between side of palpable tumor and side of pelvic lymph node metastasis in clinically localized prostate cancer.

Of 411 patients with palpable but clinically localized (Stages B or C) adenocarcinoma of the prostate, 100 (24.3%) were found at complete bilateral pelvic lymphadenectomy to have one or more lymph nodes positive for metastasis. These patients were divided into five subgroups on the basis of the location of the palpable tumor at digital rectal examination: left side only, left predominantly, both sides, right side predominantly, or right side only. Among 35 patients with positive nodes and a palpable tumor limited to one side of the prostate (clinically unilobar), metastases were found in the ipsilateral pelvic lymph nodes in 29 (83%). Only 6 (17%) of the patients had contralateral metastasis alone. A unilateral pelvic lymphadenectomy (ipsilateral to the side of the largest palpable tumor, or on either side if the tumor were bilateral) would have detected 80% of the patients with positive lymph nodes, with a positive predictive value of 100% and a negative predictive value of 94%. Lymph node metastases in patients with clinically localized palpable prostate cancer are most likely to be found on the same side as the palpable tumor and are considerably less likely to be found on the contralateral side alone. If frozen section examination of lymph nodes or laparoscopic lymph node dissection is planned before definitive therapy for prostate cancer, the pelvic lymph nodes ipsilateral to the side of the palpable tumor should be removed first.

Humans↗
PubMed1992

Semen quality and endocrine parameters after acute testicular torsion.

Of 16 postpubertal patients evaluated following testicular torsion 9 were treated with detorsion and bilateral orchiopexy (detorsion group), and 7 were treated with ipsilateral orchiectomy and contralateral orchiopexy (orchiectomy group). Each patient was evaluated with regard to semen quality, endocrine parameters (follicle-stimulating hormone, luteinizing hormone and testosterone) and the presence or absence of semen antisperm antibodies. These data were compared to similar data from a group of proved fertile semen donors. The semen quality in the detorsion group did not differ significantly from that of controls (p = 0.25) but follicle-stimulating hormone was significantly elevated compared with that of controls before and after stimulation with gonadotropin-releasing hormone. The orchiectomy group, which had been subjected to prolonged torsion (mean 69 hours), demonstrated a significant decrease in semen quality compared with semen quality in controls (p = 0.001), with average sperm density of only 29.0 million per ml. Baseline and post-stimulation levels of follicle-stimulating hormone in the orchiectomy group were also significantly abnormal when compared with those in controls and in the detorsion group. Our study demonstrates that testicular damage (changes in semen quality and/or endocrine parameters) occurs in the ipsilateral and contralateral testis following torsion, regardless of treatment modality. However, with early intervention by detorsion and testicular salvage, subsequent semen quality is likely to remain within normal limits. Late surgical intervention, even with removal of the nonviable testes, may result in significant impairment of semen quality.

Acute Disease↗
PubMed1992

Relation of triglyceride metabolism and coronary artery disease. Studies in the postprandial state.

The status of fasting triglycerides as a risk factor for coronary artery disease (CAD) has been considered weak because in multivariate analyses, triglycerides tend to be eliminated by high density lipoprotein (HDL) cholesterol. To further evaluate the role of triglycerides in CAD, we employed postprandial lipemia as a more informative means of characterizing triglyceride metabolism. In 61 male subjects with severe CAD and 40 control subjects without CAD as verified by angiography, we measured cholesterol; triglycerides; HDL cholesterol; HDL2 cholesterol; and apolipoproteins A-I, A-II, and B in fasting plasma and triglycerides before and 2, 4, 6, and 8 hours after a standardized test meal. Both the maximal triglyceride increase and the magnitude of postprandial lipemia (area under the triglyceride curve over 8 hours after the meal) were higher in cases than in control subjects. Single postprandial triglyceride levels 6 and 8 hours after the meal were highly discriminatory (p < 0.001), and by logistic-regression analysis displayed an accuracy of 68% in predicting the presence or absence of CAD. In this respect, accuracy was higher than that of HDL2 cholesterol (64%) and equal to that of apolipoprotein B (68%), the most discriminatory fasting parameter. Multivariate logistic-regression analysis was performed to reduce the number of risk factors to those that were statistically independent. This statistical procedure selected postprandial but not fasting triglycerides into the most accurate multivariate model, which also contained the accepted risk factors HDL2 cholesterol, apolipoprotein B, and age. This model classified 82% of subjects correctly. We conclude that triglycerides are independent predictors of CAD in multivariate analyses including HDL cholesterol, provided that a challenge test of triglyceride metabolism such as postprandial lipemia is used. The study suggests that the metabolism of triglycerides is a critical determinant of cholesterol metabolic routing. The findings support the concept that the negative association between HDL cholesterol levels and CAD actually originates in part from a positive relation between CAD and plasma triglycerides, as ascertained in the postprandial state.

Adult↗
PubMed1991

Ambulatory electrocardiography in dogs.

Twenty-four hour ambulatory electrocardiographic recording using a Medilog tape recorder was attempted in 16 healthy pet dogs weighing between 18.4 and 34 kg, while they were living in familiar surroundings. Full 24-hour records were obtained from 10 of them and recordings of more than 10 hours duration from two others; and the findings in these recordings were similar. Maximum heart rates ranged between 110 and 300 beats/minute and the minimum rates ranged between 17 and 46 beats/minute. Intermittent ventricular premature complexes were recorded from these apparently healthy dogs and all but one dog demonstrated a sinus pause, longer than two seconds; the longest pause was 5.7 seconds. The pauses were associated with marked sinus arrhythmia and occurred in both brachycephalic and non-brachycephalic breeds.

Animals↗
PubMed1991

Factors determining improvement in left ventricular function after reperfusion therapy for acute myocardial infarction: primacy of baseline ejection fraction.

Improvement in left ventricular ejection fraction is a measure of salvage of ischemic myocardium after reperfusion therapy for acute myocardial infarction. The degree of improvement in left ventricular ejection fraction may be influenced by many factors. Therefore, 137 patients in whom paired radionuclide angiograms were obtained within 24 h of acute infarction and before hospital discharge were retrospectively evaluated to determine which factors most affect improvement in ejection fraction. Only baseline ejection fraction correlated significantly with improvement in ejection fraction by both univariate analysis (ejection fraction as a continuous variable; p less than 0.001; ejection fraction as a categorical variable, less than or equal to 45% versus greater than 45%, p less than 0.0001) and multivariate analysis (p less than 0.0001). Reperfusion status (patent versus occluded infarct artery) and extent of coronary artery disease (one, two or three vessel) were significant factors by multivariate but not by univariate analysis. Location of infarction, treatment modality and time to treatment did not correlate with change in ejection fraction by either statistical technique. Thus, of those factors tested, baseline left ventricular ejection fraction is the most potent predictor of improvement in ventricular function after acute infarction. Knowledge of baseline ejection fraction may be helpful in deciding whether to treat some patients with equivocal indications or contraindications for reperfusion therapy. Clinical trials of reperfusion strategies should stratify patients on the basis of baseline ejection fraction if ejection fraction is to be used as an end point for myocardial salvage.

Adult↗
PubMed1991

A comparison of the morphological features of cancer arising in the transition zone and in the peripheral zone of the prostate.

To determine the characteristics of transition zone and peripheral zone prostate cancer, we examined a series of 42 stage A and 54 stage B radical prostatectomy specimens with particular attention to the number of separate foci of cancer, zone of origin, volume and grade of each focus, and presence of severe intraductal dysplasia (high grade prostatic intraepithelial neoplasia), extra-capsular extension and seminal vesicle invasion associated with cancer in each zone. We found that there were fundamental differences between transition zone and peripheral zone cancers, and that the features that characterize these tumors were apparent in stages A and B disease. Although the total tumor burden was similar in stages A (3.98 cc) and B (4.56 cc) disease, stage A cancer tended to be multifocal (3.1 tumors per prostate) and more diffuse. While 81% of stage A prostate specimens contained a tumor of transition zone origin and 93% had cancer of peripheral zone origin, transurethral resection of the prostate sampled a transition zone cancer in 77% and a peripheral zone cancer in 31% (8% had both types). Stage B cancer tended to be more focal (2.3 cancers per prostate). All stage B prostate specimens contained a peripheral zone cancer and 43% had a transition zone cancer as well. In only 1 stage B cancer patient was the transition zone tumor the palpable or index cancer. In stages A and B disease, peripheral zone tumors were less well differentiated (median Gleason sum 6 and 7) than transition zone tumors (5 and 5, respectively) and more likely to extend through the capsule (44% versus 11%). Seminal vesicle invasion arose from 19% of the peripheral zone but none of the transition zone cancers. Peripheral zone tumors were almost always (93%) associated with high grade prostatic intraepithelial neoplasia, while none of the transition zone cancers was so associated. For peripheral zone disease there was a moderate correlation between volume and grade (tau = 0.46, p less than 0.001) so that the larger the tumor the higher the Gleason sum but within transition zone disease this correlation was poor (tau = 0.23) and not statistically significant (p greater than 0.05). Extracapsular extension occurred at a smaller volume with peripheral zone cancer (mean 3.86, minimum 0.06 cc) than transition zone cancer (mean 4.98, minimum 0.39 cc). Cancer that arises in the transition zone appears to have a different histogenesis, is associated with more favorable pathological features and may have less malignant potential than tumors that arise in the peripheral zone.

Aged↗
PubMed1991

Cigarette smoking and other vascular risk factors in vasculogenic impotence.

A total of 132 consecutive patients with erectile impotence underwent extensive evaluation, including vascular evaluation with intracavernous injection of papaverine and penile duplex ultrasonography, to determine the etiology of impotence. Three vascular risk factors, smoking, diabetes mellitus and hypertension, were investigated for their impact on vasculogenic impotence. The patients were divided into four groups: one with no risk factors, one with one vascular risk factor, one with two vascular risk factors, and one with all three risk factors. The results of penile vascular evaluation in these patient groups were compared. The incidence of penile vascular impairment was found to be higher in patients with one vascular risk factor than in those with none. The proportion of abnormal penile vascular findings significantly increased as the number of risk factors increased. These data confirm the important role of vascular risk factors, smoking, diabetes mellitus, and hypertension, in the pathogenesis of organic impotence.

Diabetes Mellitus↗
PubMed1991

Ten weeks of intermittent hypocalcemic stimulation does not produce functional parathyroid hyperplasia.

Hypocalcemia is a major stimulus for parathyroid hormone secretion and presumably the major cause of parathyroid hyperplasia in chronic hypocalcemic syndromes. We could find no data to indicate what degree, duration, or frequency of hypocalcemia is needed to produce parathyroid hyperplasia in humans. We have monitored the effects of thrice weekly hypocalcemic parathyroid stimulation for 10 weeks. Measurements were made during a study designed to test the feasibility of carrying out a randomized, blinded trial of "chelation therapy," a widely used but unproven method to treat atherosclerotic symptoms. Eight patients received infusions of disodium ethylenediaminetetraacetic acid (EDTA) and six received placebo infusions thrice weekly for ten weeks. The EDTA infusions (50 mg/kg over three hours) lowered serum ionized calcium at two hours by an average of 0.20 mmol/L and trebled the immunoreactive parathyroid hormone (iPTH) value. Basal serum iPTH, ionized calcium and 1,25-dihydroxyvitamin D values, measured just before the infusion, did not change significantly after 10 weeks of treatment with either EDTA or placebo. The increment in serum iPTH produced by the EDTA-induced hypocalcemia was also unchanged. Lowering ionized serum calcium to values below the normal range three times a week for 10 weeks is not a sufficient stimulus to cause a detectable increase in basal or stimulated parathyroid function.

Aged↗
PubMed1990

Development of cholesterol homeostatic memory in the rat is influenced by maternal diets.

The hypothesis that dietary factors in early life modify the extent of adaptive responses in adult life was tested in rats. During the gestational and lactational periods, pregnant rats were fed either a high-fat (HF) or low-fat (LF) diet (corn oil, 15% or 2%, wt/wt) until 30 days postpartum. The offspring were maintained on standard chow for an additional 100 days and fed a HF diet for 1, 3, 7, or 21 days. Upon challenge for 3 days, rats born to dams fed the HF diet showed a more rapid hypercholesterolemic response when compared with rats born to dams fed a LF diet (mean +/- S.D., 151 +/- 14 mg/dL v 122 +/- 6 mg/dL; P less than .001). Higher levels of cholesterol were associated with elevated levels of apolipoprotein (apo) B (24.0 +/- 4 mg/dL v 15.8 +/- 3 mg/dL; P less than .05) and apo E (31.0 +/- 4 mg/dL v 24.7 +/- 3 mg/dL; P less than .05). Further comparison of the hypercholesterolemic response between the two groups of animals showed increases in cholesterol in all major lipoprotein classes, cholesterol enrichment at the expense of triglyceride (TG) in very-low-density lipoprotein (VLDL), and elevation of apo E-containing high-density lipoprotein (HDL). Examination at longer time periods of HF challenge showed that apo E levels of the HF-exposed animals remained elevated compared with similarly challenged rats born to dams fed the LF diet (35 +/- 3.8 mg/dL v 26 +/- 2.7 mg/dL; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Comparison of penile duplex ultrasonography with nocturnal penile tumescence monitoring for the evaluation of erectile impotence.

A total of 50 patients with erectile dysfunction underwent comprehensive evaluation, including vascular evaluation with penile duplex ultrasonography and papaverine injection, as well as nocturnal penile tumescence monitoring. The latter was performed in a sleep laboratory setting in all patients. The results of penile duplex ultrasonography with papaverine injection were classified as 18 patients with normal vascular findings, 22 with arterial insufficiency, 3 with the pelvic steal syndrome and 7 with isolated venous leakage. Of the patients 15 had normal ultrasonographic and nocturnal penile tumescence findings, 29 had abnormal ultrasonographic vascular and nocturnal penile tumescence findings, 3 had abnormal ultrasonographic vascular findings and normal nocturnal penile tumescence (including 1 with the pelvic steal syndrome as evidenced by penile brachial index) and 3 had normal ultrasonographic vascular findings and abnormal nocturnal penile tumescence (including 2 with neurogenic erectile dysfunction). Penile duplex ultrasonography with papaverine injection appears to be a useful objective method to evaluate vasculogenic impotence and to correlate favorably with nocturnal penile tumescence monitoring. It also may have a higher yield than nocturnal penile tumescence monitoring in patients with the pelvic steal syndrome. While nocturnal penile tumescence is impaired in patients with neurogenic impotence, penile duplex ultrasonography with papaverine injection reveals, as expected, normal findings in patients with neurogenic impotence and normal vascular systems.

Adult↗
PubMed1990

A center-based program for exercise change among black-American families.

A center-based program was designed and implemented to promote aerobic physical activity among healthy Black-American families with children in the fifth through seventh grades. Ninety-four Black-American families were actively recruited and randomly assigned to an experimental or control group. Families in the experimental group were encouraged to participate in a program with the following features: one education and two fitness sessions per week for 14 weeks; educational sessions that included individual counseling, small group education, aerobic activity, and snack components; located in a convenient building cherished by the community; aerobic activity sessions in a fitness center outfitted and staffed according to modern characteristics; a variety of incentives including free transportation and babysitting and reminders to promote attendance. Percent participation was low, with about 20% participating in the desired fitness center sessions by the end of the program. As a result of low participation, no differences were detected between experimental and control groups on indicators of cardiovascular fitness. In postprogram interviews, conflicts with work and school events were the most commonly reported reasons for nonattendance. We concluded that because of difficulties in attendance, center-based programs appear to have limited value as the sole modality for intervention in public health programs for promoting physical activity among healthy, low income Black-American families with young children. More comprehensive community-based programs are likely to be needed.

Adult↗
PubMed1990

Effect of blood collection and processing on radioimmunoassay results for apolipoprotein B in plasma.

We studied the effects of different blood collection and processing procedures on quantification of apolipoprotein (apo) B by radioimmunoassay. High-density lipoprotein subfractions HDL3 and HDL2 and isolated apoA-I did not cross-react in the assay. Analytical recovery of apoB at different doses of very-low- and low-density lipoproteins were complete. Inter- and intra-assay coefficients of variation (CVs) averaged 7.4% and 6.0%, respectively. Blood from 20 subjects was collected into tubes containing EDTA alone or EDTA with antiproteolytic and antioxidant agents; one half of each plasma was separated immediately, half after 3 h at 4 degrees C. Regardless of the addition of protective agents or the time difference in separating plasma from other blood elements, freezing plasma at -70 degrees C decreased apoB content a similar amount, an average of 6.8%. This loss of apoB immunoreactivity was not related to apoB content in fresh plasma. Analysis of variance showed no differential effect on apoB content by the various additions to whole blood or plasma. No additional apoB content was lost in once-frozen aliquots of three human plasma pools during storage at -70 degrees C for up to 18 months. We conclude that concentrations of apoB in human plasma can be measured reliably after long-term storage, although the absolute value may decrease slightly as a result of freezing.

Analysis of Variance↗
PubMed1989

Evaluation of vasculogenic erectile impotence using penile duplex ultrasonography.

A total of 140 patients underwent penile vascular evaluation with intracavernous papaverine injection combined with duplex ultrasonography. Of these patients 8 were potent men who were evaluated for reasons other than erectile failure. These potent men were used as controls to obtain normal values. The remaining 132 patients had erectile impotence of various etiologies. Real-time imaging with high resolution, high frequency probes allowed for visualization of the cavernous arteries along the entire length in addition to accurate measurement of the diameter. Simultaneous selectively focused Doppler ultrasonography was used to measure the blood velocity and other vascular parameters in the cavernous and dorsal arteries. Comparison of measurements before and after papaverine injection allowed for objective interpretation of the injection results. The results were analyzed and compared to other data available on the same patients, such as history and physical examination, nocturnal penile tumescence, penile blood pressures, selective arteriography and dynamic cavernosography. In addition to the 8 potent men, there were 35 patients (27% of the impotent patients) whose vascular findings were normal. A total of 78 patients (59% of the impotent patients) had arterial insufficiency; a subgroup of 13 patients had the pelvic arterial steal syndrome. Dynamic cavernosography confirmed venous leak in all 19 patients (14% of the impotent patients) whose penile duplex ultrasonography suggested the possibility of a venous leak. Ten patients (7%) had prolonged erection after papaverine injection and they were managed without consequences. One patient had a small hematoma that resolved uneventfully. Penile duplex ultrasonography was a helpful and objective method to evaluate vasculogenic impotence.

Adult↗
PubMed1988

Characteristics of the recurrently hospitalized adult. An information synthesis.

Hospital use in the US is concentrated in the approximately 2% of the population that is repeatedly hospitalized. Using the research integration technique of information synthesis, empirical studies of readmission were assembled and analyzed to determine the demographic and clinical characteristics of the repeatedly hospitalized adult. The authors' synthesis of articles that met preset criteria of relevance and validity indicated that clinical variables show a more consistent association with readmission than demographic variables. Diagnosis, prior use, and disability appear to be strong predictors of an individual's level of hospital use. Demographic variables with consistent positive associations with readmission include being widowed, living with relatives other than a spouse, decreasing income, living in the South, and living in an urban area, but available work does not indicate whether these demographic variables are independent predictors of readmission or merely markers of an increased prevalence of chronic disease. Findings indicate that future investigations of the predictors of this costly pattern of hospital use will be most illuminating if illness-related factors such as diagnosis, disease severity, functional status, and usage history are carefully specified and examined.

Adolescent↗
PubMed1988

Chicken homolog of the mos proto-oncogene.

We compared the sequence and properties of the chicken mos homolog with the previously characterized mouse and human c-mos genes. Sequence analysis revealed one major open reading frame of 1,047 base pairs encoding a protein of 349 amino acids. Both the nucleotide sequence and the deduced amino acid sequence showed 62% overall homology to mouse and human c-mos, but regions of higher conservation (approximately 70%) occurred in the putative ATP-binding and kinase domains. We detected mos transcripts by Northern (RNA) analyses in RNA prepared from chicken and quail ovaries and testes. Evidence for low levels of mos RNA expression in adult chicken heart, kidney, and spleen and in the entire embryo was obtained by S1 nuclease protection experiments. In contrast to the low transforming efficiency of human c-mos when linked to a mouse retroviral long terminal repeat element, chicken c-mos transformed NIH 3T3 cells as efficiently as mouse c-mos did. We also show that chicken primary embryo fibroblasts were morphologically altered when infected with an avian retroviral vector containing the chicken c-mos coding region.

Amino Acid Sequence↗
PubMed1988

Ethnic variation in blood pressure among preadolescent children.

As part of a study on methods for assessing diet and exercise among 163 3rd to 6th grade students, data were collected on blood pressure, diet, urinary electrolytes, aerobic activity, resting pulse, and body composition. Data were collected on a stratified sample, with almost equal numbers of children of both sexes from 3rd or 4th and 5th or 6th grades; from three ethnicities: Anglo-, Black- and Mexican-American. Three resting blood pressures were obtained using a Hawksley random zero sphygmomanometer. Data analytic procedures relied on analyses of variance and covariance to assess differences across design factors in blood pressure, with dietary sodium, resting pulse, body surface area, and energy expended as covariates. No differences were detected across ethnic groups in systolic pressures, but Mexican-American children were shown to have significantly higher diastolic fourth phase pressures than Anglo- or Black-American children. Only the dietary variables differed across ethnic groups, but not in the same pattern. Differences in the covariates did not account for the difference across ethnic groups in diastolic pressures.

Analysis of Variance↗