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Biomedical subjects

D Wagner

Publications and source records attributed to D Wagner.

At least 55 records · Page 3Linked to original sources
PubMed2000

Prediction of survival for older hospitalized patients: the HELP survival model. Hospitalized Elderly Longitudinal Project.

OBJECTIVE: To develop and validate a model estimating the survival time of hospitalized persons aged 80 years and older. DESIGN: A prospective cohort study with mortality follow-up using the National Death Index. SETTING: Four teaching hospitals in the US. PARTICIPANTS: Hospitalized patients enrolled between January 1993 and November 1994 in the Hospitalized Elderly Longitudinal Project (HELP). Patients were excluded if their length of hospital stay was 48 hours or less or if admitted electively for planned surgery. MEASUREMENTS: A log-normal model of survival time up to 711 days was developed with the following variables: patient demographics, disease category, nursing home residence, severity of physiologic imbalance, chart documentation of weight loss, current quality of life, exercise capacity, and functional status. We assessed whether model accuracy could be improved by including symptoms of depression or history of recent fall, serum albumin, physician's subjective estimate of prognosis, and physician and patient preferences for general approach to care. RESULTS: A total of 1266 patients were enrolled over a 10-month period, (median age 84.9, 61% female, 68% with one or more dependency), and 505 (40%) died during an average follow-up of more than 2 years. Important prognostic factors included the Acute Physiology Score of APACHE III collected on the third hospital day, modified Glasgow coma score, major diagnosis (ICU categories together, congestive heart failure, cancer, orthopedic, and all other), age, activities of daily living, exercise capacity, chart documentation of weight loss, and global quality of life. The Somers' Dxy for a model including these factors was 0.48 (equivalent to a receiver-operator curve (ROC) area of 0.74, suggesting good discrimination). Bootstrap estimation indicated good model validation (corrected Dxy of 0.46, ROC of 0.73). A nomogram based on this log-normal model is presented to facilitate calculation of median survival time and 10th and 90th percentile of survival time. A count of geriatric syndromes or comorbidities did not add explanatory power to the model, nor did the hospital of patient recruitment, depression, or the patient preferences for general approach to care. The physician's perception of the patient's preferences and the physician's subjective estimate of the patient's prognosis improved the estimate of survival time significantly. CONCLUSIONS: Accurate estimation of length of life for older hospitalized persons may be calculated using a limited amount of clinical information available from the medical chart plus a brief interview with the patient or surrogate. The accuracy of this model can be improved by including measures of the physician's perception of the patient's preferences for care and the physician's subjective estimate of prognosis.

Activities of Daily Living↗
PubMed2000

Length of stay and therapeutic intervention allow estimation of in-hospital resource use independent of site and inflation.

OBJECTIVES: To develop and evaluate a model to estimate inpatient resource utilization for seriously ill patients using periodic medical record abstraction and hospital length of stay. DESIGN: A prospective cohort study of prognoses and preferences and outcomes of seriously ill hospitalized adults. The predictive model was based on the Therapeutic Intervention Scoring System (TISS), length of stay (LOS), and hospital site, and was developed on Phase I data and validated on Phase II data. SETTING: Five teaching hospitals in the United States PARTICIPANTS: The derivation sample included 4301 patients enrolled in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment (SUPPORT). The validation sample included 4804 patients. MEASUREMENTS: Hospital charges were correlated with the product of hospital length of stay and average score from the TISS. Model fit assessment used R2 for total hospital charges. RESULTS: The correlation between hospital charges and the final model, after adjusting for site differences, was 0.86. The correlation was similar when validating the model in an independent data set. CONCLUSIONS: We present a method to estimate hospital resource utilization that is independent of site and inflation and can estimate actual costs in multiyear, multisite research endeavors.

Aged↗
PubMed2000

Compensatory sleep response to 12 h wakefulness in young and old rats.

There is a pronounced decline in sleep with age. Diminished output from the circadian oscillator, the suprachiasmatic nucleus, might play a role, because there is a decrease in the amplitude of the day-night sleep rhythm in the elderly. However, sleep is also regulated by homeostatic mechanisms that build sleep drive during wakefulness, and a decline in these mechanisms could also decrease sleep. Because this question has never been addressed in old animals, the present study examined the effects of 12 h wakefulness on compensatory sleep response in young (3.5 mo) and old (21.5 mo) Sprague-Dawley and F344 rats. Old rats in both strains had a diminished compensatory increase in slow-wave sleep (SWS) after 12 h of wakefulness (0700-1900, light-on period) compared with the young rats. In contrast, compensatory REM sleep rebound was unaffected by age. To assess whether the reduced SWS rebound in old rats might result from loss of neurons implicated in sleep generation, we counted the number of c-Fos immunoreactive (c-Fos-ir) cells in the ventral lateral preoptic (VLPO) area and found no differences between young and old rats. These findings indicate that old rats, similar to elderly humans, demonstrate less sleep after prolonged wakefulness. The findings also indicate that although old rats have a decline in sleep, this cannot be attributed to loss of VLPO neurons implicated in sleep.

Adaptation, Physiological↗
PubMed2000

The oxidative metabolism of estradiol conditions postmenopausal bone density and bone loss.

Because lifelong exposure to estrogen is a strong determinant of bone mass, we asked whether metabolic conversion of estrogen to either inactive or active metabolites would reflect postmenopausal bone mineral density (BMD) and rate of bone loss. Biochemical markers of inactive estrogen metabolites, urinary 2-hydroxyestrogen (2OHE1) and 2-methoxyestrogen (2MeOE1), and active metabolites, urinary 16alpha-hydroxyestrone (16alphaOHE1), estradiol (E2), and estriol (E3), were determined in 71 untreated, healthy postmenopausal women (age, 47-59 years) followed prospectively for 1 year. Urinary 2MeOE1 was correlated negatively with baseline vertebral (anteroposterior [AP] projection, r = -0.23 andp < 0.05; lateral view, r = -0.27 and p < 0.05) and proximal femur bone density measured by dual-energy X-ray absorptiometry (DXA; total, r = -0.38 and p < 0.01; neck, r = -0.28 and p = 0.02; trochanter, r = -0.44 and p < 0.01). BMDs of women in the lowest quartile of urinary 2MeOE1 (< 15 ng/g) were significantly higher than those in the highest quartile at all skeletal sites (p < 0.05). Likewise, women in the lowest quartile of urinary 2OHE1/16alphaOHE1 ratio (< 1.6) did not experience bone loss after 1 year, in contrast to women in the higher quartiles. We propose that the rate of inactivation of estrogens through 2-hydroxylation may contribute to postmenopausal osteoporosis.

Absorptiometry, Photon↗
PubMed2000

Pollen viability reduction as a potential cost of ant association for Acacia constricta (Fabaceae).

Field studies investigating the impact of ants on the reproduction of plants bearing extrafloral nectaries have traditionally focused on seed production, a component of female fitness. The purpose of this study was to test whether ants can affect the pollen viability, a component of male fitness, when they visit flowers of the shrub Acacia constricta. Acacia constricta inflorescences hand-pollinated with flowers over which Formica perpilosa ants had crawled set significantly fewer seed pods than inflorescences hand-pollinated by control flowers that had no contact with ants. Many ant species secrete antibiotic substances onto the integument that render pollen inviable, and these secretions are probably the mechanism for reduced pollen viability in this study. The ratio of seed pods produced by self-pollinated inflorescences to those produced by cross-pollinated inflorescences was 0.16, indicating that A. constricta is largely self-incompatible. Because F. perpilosa workers forage primarily on the acacia tree under which they nest, they are unlikely to serve as efficient vectors of outcrossing. Previous work showed that A. constricta shrubs with F. perpilosa ants produce approximately twice as many seeds as similarly sized plants not so associated. The results indicate that association with F. perpilosa could cause a reproductive trade-off for A. constricta: benefits to female function may be accompanied by costs to male function. Selection to discourage ant visitation to flowers may have affected the pollination biology of this and other ant-associated plant species.

Journal Article↗
PubMed2000

Mechanisms of Mycobacterium avium pathogenesis.

Infections caused by Mycobacterium avium are common in AIDS patients and patients with chronic lung diseases. The bacterium can be acquired both through the intestinal route and respiratory route. M. avium is capable of invading mucosal epithelial cells and translocating across the mucosa. The bacterium can infect macrophages, interfering with several functions of the host cell. The host defense against M. avium is primarily dependent on CD4+ T lymphocytes and natural killer cells. Activated macrophages can inhibit or kill intracellular bacteria by mechanisms that are currently unknown, but M. avium can invade resting macrophages and suppress key aspects of their function by triggering the release of transforming growth factor beta and interleukin 10. Co-infection with HIV-1 appears to be mutually beneficial, with both organisms growing faster.

AIDS-Related Opportunistic Infections↗
PubMed2000

Distribution of hypocretin-containing neurons in the lateral hypothalamus and C-fos-immunoreactive neurons in the VLPO.

The present study investigated the distribution of neurons implicated in the regulation of sleep in three species generally used in sleep research, i.e., mice, rats and cats. We focused on sleep active neurons in the ventral lateral preoptic (VLPO) area and the hypocretin/orexin-containing neurons in the lateral hypothalamus. The latter groups of neurons were found recently to play an important role in the regulation of REM sleep. The expression of the transcription factor, c-Fos, was used to identify the VLPO. In mice and rats, in response to sleep, a discrete cluster of c-Fos positive cells was found in the VLPO. In mice, this cluster was located more medially compared to the rat, and as in the rat, galanin immunostained neurons were found in the VLPO. In the cat, c-Fos positive cells did not segregate to a specific location but were more diffusely represented in the preoptic area. In all three species, orexin/hypocretin-containing neurons were located only in the lateral hypothalamus with the distribution being more diffuse in the cat. The grouping of sleep-active cells in rodents makes it feasible to extract these cells for tissue culture and molecular analysis. Moreover, given that rodents have a distinct circadian distribution of sleep-wakefulness, the connectivity with the suprachiasmatic nucleus can also be determined.

Animals↗
PubMed1999

Transcriptional activation of APETALA1 by LEAFY.

Plants produce new appendages reiteratively from groups of stem cells called shoot apical meristems. LEAFY (LFY) and APETALA1 (AP1) are pivotal for the switch to the reproductive phase, where instead of leaves the shoot apical meristem produces flowers. Use of steroid-inducible activation of LFY demonstrated that early expression of AP1 is a result of transcriptional induction by LFY. This AP1 induction is independent of protein synthesis and occurs specifically in the tissues and at the developmental stage in which floral fate is assumed. Later expression of AP1 appears to be only indirectly affected by LFY.

Arabidopsis↗
PubMed1999

[Cardiovascular diseases and sports].

Regular physical activity has been found helpful--contrary to previous belief--in heart disease and has a positive effect on the wellbeing of the patient. A positive effect on the mortality rate from coronary heart disease with normal left ventricular function has been found. The physical performance of the patient with impaired left ventricular function increases via reduction of peripheral vascular resistance, increased blood flow and more efficient muscle metabolism. Patients with arterial hypertension profit equally from a regular workout. But in the presence of end organ damage high intensity sports should be avoided. In cases of congenital valvular disease with heart failure and right and left ventricular congestion the activity level should be adapted to the symptoms. Hypertrophic cardiomyopathy is the most common reason for sudden death in young athletes. If diagnosed, all high intensity sports are strictly forbidden. Threatening ventricular arrhythmias are seldom found in young adults. Symptomatic arrhythmias should be investigated for organic causes.

Adult↗
PubMed1999

Evaluation of serological screening of cadaveric sera for donor selection for cornea transplantation.

Human corneas are explanted for grafting as late as 72 h after death, for example, from medical examiner cases. Currently, infection of the donor with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) is excluded in most cornea banks by serological testing of the cadaveric serum only. The reliability of this strategy was investigated by testing paired cadaveric and premortem sera of 33 potential donors. Results were discordant in 17 of 33 donors by at least one assay. Most frequently, HBsAg enzyme-linked immunosorbent assay (ELISA) yielded false-positive results with the cadaveric serum (16 of 33 serum pairs). Virus safety of the graft was affected in a single case, which was HCV antibody negative in the cadaveric serum, but positive in the premortem serum (confirmed by HCV-RIBA strip immunoassay). Forensic DNA profiling by polymerase chain reaction (PCR) of both serum samples confirmed that these were derived from the same individual. In conclusion, the results indicate that serological testing of cadaveric sera is not a reliable method for screening of potential cornea donors, and may not be sufficient for the virus safety of cornea grafts. Therefore, other screening strategies such as detection of viral nucleic acids by PCR should be evaluated.

Adult↗
PubMed1999

The use of granulocyte colony stimulating factor to promote wound healing in a neutropenic patient after head and neck surgery.

BACKGROUND: Neutropenia and neutrophil dysfunction, in association with a variety of diseases, has been shown to play a role in poor wound healing. Wound breakdown with fistula formation in patients undergoing total laryngectomy results in significant morbidity and increased hospital stay. Although malnutrition, prior radiation, diabetes, and other diseases are recognized as factors predisposing patients with head and neck cancer to developing fistulas, neutrophil dysfunction should also be considered. Granulocyte colony stimulating factor (G-CSF) has been used successfully to treat neutropenia and neutrophil dysfunction. METHODS: This study was conducted as a case report. RESULTS: We present the first report of a neutropenic head and neck cancer patient with a persistent wound of 6 months' duration who showed dramatic improvement after treatment with G-CSF. CONCLUSION: We conclude that G-CSF may represent a useful adjunct in patients with persistent wound healing problems and neutropenia despite adequate treatment by conventional means. Further clinical experience with G-CSF in patients with delayed healing is indicated.

Cutaneous Fistula↗
PubMed1999

Peptostreptococcus ivorii-associated skin abscess in a HIV-infected patient.

Peptostreptococcus ivorii, a recently described species of gram-positive anaerobic coccus, has so far rarely been found in human infections. The isolation of this anaerobe from a polybacterial skin abscess in a HIV-infected patient, which formed after antiretroviral therapy had been discontinued is reported. Local treatment led to the abscess healing without specific antibiotics. As the type strain was isolated from a mixed infected leg ulcer, Peptostreptococcus ivorii could play an important role in synergistic infections of the skin.

Journal Article↗
PubMed1999

[Psychobiological aspects of posttraumatic stress disorder].

The exposure to a traumatic event may result in posttraumatic stress disorder (PTSD), which is characterized by a complex symptomatology, clustered into three groups of symptoms, i.e. intrusive memories, avoidance behavior, and hyperarousal. Since PTSD is a stress reaction, alterations of stress-responses of neurobiological systems have been examined in patients suffering from PTSD. The investigation of biological parameters refers to the hypothalamic-pituitary-adrenal axis (HPA), studies of the noradrenergic and the endogenous opiate system as well as psychophysiological and neuroimaging studies. Besides others, the observed biological dysregulations refer to hypocortisolism with an enhanced negative feedback of the HPA axis, enhanced noradrenergic activity, and neuroanatomical changes. To elucidate the specificity of this findings for PTSD, the dysregulations will be discussed with reference to findings in major depression and somatoform disorders.

Brain↗
PubMed1999

Consultation-liaison service in the general hospital: effects of cognitive-behavioral therapy in patients with physical nonspecific symptoms.

Nearly 15% of patients referred to a general hospital psychological medicine consultation service met DSM criteria for somatoform disorders or showed psychological factors affecting physical conditions. In a case-control control study of patients meeting these diagnostic criteria. outcomes were compared of 21 consecutively referred patients who received a course of cognitive-behavioral therapy (CBT) in addition to standard hospital treatment (SHT) and another 21 patients who received SHT alone. Compared with the SHT group, those who received CBT treatment showed significantly decreased bodily complaints and negative mood, better insight into the psychosomatic causes of their complaints, and a high motivation for subsequent psychotherapy.

Adult↗
PubMed1999

A comparison of the interpretation of digitized and videotape recorded echocardiograms.

Conventional echocardiograms are typically recorded on videotape and later reviewed and interpreted by a physician. Although videotape recording is an excellent medium for this purpose, it does have several disadvantages, which may be overcome by digital storage. This study compared the diagnostic accuracy of digitized and videotape recorded echocardiograms. Echocardiographic examinations (n = 110) were recorded simulta-neously on videotape and were digitized with a commercially available frame grabber system. Images were transmitted by an Ethernet link to the network-based computer system and compressed with a nondestructive compression algorithm. Images were reviewed on a personal computer. Images were interpreted by 3 observers, and differences in interpretation were documented. There were 274 findings in 110 patients. Exact agreement in interpretation was found in 83%. A major discrepancy occurred in 2%, and a minor discrepancy occurred in 15%. Most discrepancies occurred in the setting of valvular heart disease. When compared with a consensus interpretation, no significant difference was seen in the number of errors between the digital and videotape interpretation. We conclude that the interpretation of a properly recorded digitized echocardiographic examination yields interpretations equivalent to those of videotape recordings.

Echocardiography↗
PubMed1999

Influenza vaccination in heart transplant recipients.

Seventy-nine heart transplant recipients were vaccinated with a trivalent influenza virus vaccine 1996/97 containing the strains A/Singapore/6/86 (H1N1), A/Wuhan/395/95 (H3N2), and B/Beijing/184/93. The proportions of patients with protective levels of antibody (HI > or = 40) after vaccination ranged from 100% (A/Singapore [H1N1]) to 31.6% (B/Beijing) and their mean fold titer increases were lower than those recorded for vaccination of 109 healthy subjects with the same batch of vaccine. The vaccinations were tolerated well and did not result in serious side effects, such as graft rejections. Our findings indicate that influenza vaccination can induce protective antibody levels in a substantial proportion of heart transplant recipients and lend support to the recommendation to vaccinate such patients annually against influenza.

Antibodies, Viral↗