PubMed Health⌕ Search

Biomedical subjects

R Madsen

Publications and source records attributed to R Madsen.

At least 19 recordsLinked to original sources
PubMed2001

Predicting mortality in nursing home residents with lower respiratory tract infection: The Missouri LRI Study.

CONTEXT: Lower respiratory tract infection (LRI) is a leading cause of mortality and hospitalization in nursing home residents. Treatment decisions may be aided by a clinical prediction rule that identifies residents at low and high risk of mortality. OBJECTIVE: To identify patient characteristics predictive of 30-day mortality in nursing home residents with an LRI. DESIGN, SETTING, AND PATIENTS: Prospective cohort study of 1406 episodes of LRI in 1044 residents of 36 nursing homes in central Missouri and the St Louis, Mo, area between August 15, 1995, and September 30, 1998. MAIN OUTCOME MEASURE: Thirty-day all-cause mortality. RESULTS: Thirty-day mortality was 14.7% (n = 207). In a logistic analysis, using generalized estimating equations to adjust for clustering, we developed an 8-variable model to predict 30-day mortality, including serum urea nitrogen, white blood cell count, body mass index, pulse rate, activities of daily living status, absolute lymphocyte count of less than 800/microL (0.8 x 10(9)/L), male sex, and deterioration in mood over 90 days. In validation testing, the model exhibited reasonable discrimination (c =.76) and calibration (nonsignificant Hosmer-Lemeshow goodness-of-fit statistic, P =.54). A point score based on this model's variables fit to the entire data set closely matched observed mortality. Fifty-two percent of residents had low (score of 0-4) or relatively low (score of 5-6) predicted 30-day mortality, with 2.2% and 6.2% actual mortality, respectively. CONCLUSIONS: Our model distinguishes nursing home residents at relatively low risk for mortality due to LRI. If independently validated, our findings could help physicians identify nursing home residents in need of different therapeutic approaches for LRI.

Aged↗
PubMed2001

A convenient route to higher sugars by two-carbon chain elongation using Wittig/dihydroxylation reactions.

The combination of a Wittig olefination and a dihydroxylation reaction constitutes a facile synthetic protocol for the transformation of unprotected carbohydrates into higher sugars. The Wittig reaction is carried out with tert-butyl or diphenylmethyl ester stabilized phosphoranes to give (E)-configured alpha,beta-unsaturated esters as the only products in most cases. These are dihydroxylated in a diastereoselective fashion using OsO(4)/NMO. The stereochemical outcome in the dihydroxylation follows Kishi's empirical rule and gives high diastereoselectivity (5:1-8:1) when starting from sugars with the 2,3-threo configuration. When starting from sugars with the 2,3-erythro configuration, the diastereoselectivity in the dihydroxylation is low (2:1-2.5:1). As a result, the Wittig/dihydroxylation protocol is most effective for producing higher sugars with the galacto configuration at the reducing end. The two steps can either be carried out individually or, more efficiently, as a one-pot procedure.

Carbohydrates↗
PubMed2001

Efficient synthesis of enantiopure conduritols by ring-closing metathesis.

Two short synthetic approaches to enantiopure conduritols are described starting from the chiral pool. In both cases, the cyclohexene ring is assembled via ring-closing olefin metathesis. The terminal diene precursers for the metathesis reaction are prepared either from octitols or from tartaric acids. The former route involves a new method for selective bromination of the primary positions in long-chain carbohydrate polyols. Subsequent reductive elimination with zinc then generates the diene. The latter route uses a highly diastereoselective addition of divinylzinc to tartaric dialdehydes for preparation of the dienes.

Alkenes↗
PubMed2000

Usefulness of a pediatric colonoscope for colonoscopy in adults.

BACKGROUND: There are few published data on how different types of colonoscopes affect success in reaching the cecum and patient comfort. We examined the feasibility of using a pediatric colonoscope for routine colonoscopy in adults and investigated whether there were subgroups of patients in whom use of this instrument was preferable. METHODS: One-hundred fifty adults undergoing outpatient colonoscopy were randomized to colonoscopy with a standard colonoscope (Olympus CF-100L) or with a pediatric colonoscope (Olympus PCF-100). All procedures were performed by a faculty endoscopist and timed by an independent observer. After examinations, the endoscopist graded procedure difficulty and patients were given a questionnaire that assessed their experience. RESULTS: The adult (n = 77) and pediatric (n = 73) colonoscope groups were comparable in all outcomes measured, including success in reaching the cecum (91% vs. 93%, p = 0.61), mean time to reach the cecum (11.4 vs. 9.7 min, p = 0.07), mean total procedure time (21.8 vs. 21.9 min, p = 0.95), mean meperidine dose (55 vs. 52 mg, p = 0.17); median midazolam dose (2.0 mg in both groups, p = 0.10), the endoscopists' perception of procedure difficulty, and patient comfort scales. Of the 7 patients in whom colonoscopy with the adult colonoscope was unsuccessful, the cecum was reached in 4 by switching to a pediatric colonoscope (all women, 3 of whom had prior hysterectomy). In the 5 patients in whom colonoscopy with the pediatric colonoscope was unsuccessful, the cecum was reached in 1 by switching to an adult colonoscope. Including the cases in which the cecum was reached by switching to the alternative colonoscope, the overall frequency of cecal intubation was 143 of 150 (95%). Subgroup analysis disclosed no difference between the 2 groups in outcomes when gender, presence of diverticulosis, and patient size were considered. Colonoscopy with the pediatric colonoscope was more successful than with the adult instrument in reaching the cecum in women with prior hysterectomy (11 of 12 [92%] vs. 15 of 21 [71%]); however, the numbers in each group were relatively small and the difference was not significant (p = 0.22). CONCLUSIONS: The pediatric colonoscope is suitable for routine colonoscopy in adults. It is also useful in patients in whom colonoscopy with the adult colonoscope is unsuccessful in reaching the cecum (particularly in women). Additional study is needed to see if the pediatric colonoscope is actually superior to the adult colonoscopy for routine colonoscopy in women with prior hysterectomy.

Adult↗
PubMed2000

An instrument to measure symptom experience. Symptom occurrence and symptom distress.

This article describes the development of an instrument that measures symptom experience (symptom occurrence and symptom distress). The Adapted Symptom Distress Scale-2 (ASDS-2), adapted from the McCorkle and Young Distress Scale, is a 31-item, 5-point, self-report paper-and-pencil instrument that measures patients' perception of the occurrence and distress of 14 symptoms: nausea, vomiting, pain, eating, sleep, fatigue, bowel elimination, breathing, coughing, concentration, lacrimation, changes in body temperature, appearance, and restlessness. Use of the instrument yields a total score for symptom experience, scores for symptom occurrence, scores for symptom distress, and subscale scores for six symptom categories: gastrointestinal, fatigue/restlessness, concentration, pain/discomfort, respiratory, and appearance. Reliability and validity were determined with well adults (n = 97), medical-surgical patients (n = 82), and oncology patients (n = 175). Findings revealed a Cronbach's alpha of 0.91 for symptom experience, 0.90 for symptom occurrence, and 0.76 for symptom distress. Cronbach's alpha for the subscales ranged from 0.38 for appearance symptoms to 0.83 for gastrointestinal symptoms. Inclusion of symptoms reported by patients with cancer strengthened content validity. A contrasted groups approach was used to demonstrate construct validity.

Adolescent↗
PubMed2000

An evaluation of satisfaction with telemedicine among health-care professionals.

A survey was conducted among non-doctor health-care professionals in six rural counties in Missouri. The purpose of the survey was to establish baseline data to evaluate the effect of changes in the health-care sector, especially technology changes, on the job satisfaction, career satisfaction, relationships and communication activities of health professionals. The survey included three rural counties in which integrated telecommunication and interactive video telemedicine services were being installed, but before significant activities had begun, and three comparator counties without substantial integrated telecommunications infrastructure and telemedicine services. During a one-month study period, 1108 questionnaires were distributed. The total response rate was 50.1% (n = 555). Of the respondents, 30.3% indicated that technology in health-care was having a large effect on their work, although only 18.2% indicated that telemedicine and telecommunications were having a large effect. No systematic differences were found among the health professionals in the two communities at the time telemedicine equipment was being installed.

Health Knowledge, Attitudes, Practice↗
PubMed2000

Use of GHb (HbA1c) in screening for undiagnosed diabetes in the U.S. population.

OBJECTIVE: To evaluate the use of GHb as a screening test for undiagnosed diabetes (fasting plasma glucose > or =7.0 mmol/l) in a representative sample of the U.S. population. RESEARCH DESIGN AND METHODS: The Third National Health and Nutrition Examination Survey included national samples of non-Hispanic whites, non-Hispanic blacks, and Mexican Americans aged > or =20 years. Of these subjects, 7,832 participated in a morning examination session, of which 1,273 were excluded because of a previous diagnosis of diabetes, missing data, or fasting time of <8 h before examination. Venous blood was obtained to measure fasting plasma glucose and GHb in the remaining 6,559 subjects. Receiver operating characteristic curve analysis was used to examine the sensitivity and specificity of GHb for detecting diabetes at increasing GHb cutoff levels. RESULTS: GHb demonstrated high sensitivity (83.4%) and specificity (84.4%) for detecting undiagnosed diabetes at a GHb cutoff of 1 SD above the normal mean. Moderate sensitivity (63.2%) and very high specificity (97.4%) were evident at a GHb cutoff of 2 SD above the normal mean. Sensitivity at this level ranged from 58.6% in the non-Hispanic white population to 83.6% in the Mexican-American population; specificity ranged from 93.0% in the nonHispanic black population to 98.3% in the non-Hispanic white population. CONCLUSIONS: GHb is a highly specific and convenient alternative to fasting plasma glucose for diabetes screening. A GHb value of 2 SD above the normal mean could identify a high proportion of individuals with undiagnosed diabetes who are at risk for developing diabetes complications.

Adult↗
PubMed2000

Physician satisfaction with Medicaid managed care: the Missouri experience.

BACKGROUND: Medicaid managed care is important to health reform at the state level. However, little is known about physician satisfaction with these programs. We sought to measure this satisfaction in Missouri and determine its predictors. METHODS: We surveyed a random sample of primary care physicians participating in Medicaid managed care (n = 670) or traditional Medicaid (n = 670). Primary outcomes measured were physicians' satisfaction Medicaid managed care, traditional Medicaid and commercial managed care. Satisfaction was measured on a 5-point Likert-type scale. RESULTS: The response rate was 52%. Physicians participating in Medicaid managed care were less likely to be satisfied or very satisfied with Medicaid managed care (28.6%) than with commercial managed care (40%) or their previous experience with traditional Medicaid (39.7%). Among physicians participating in traditional Medicaid, 29.8% were satisfied or very satisfied with traditional Medicaid. Physicians participating in Medicaid managed care were less satisfied with clinical autonomy under that system in comparison with their previous experience with traditional Medicaid (relative difference = 10.8%, P =.001). In multiple linear regression analyses, clinical autonomy (R2 = 0.40) was a strong predictor of overall satisfaction with Medicaid managed care. CONCLUSIONS: Enhancing physicians' clinical autonomy may result in improved satisfaction with Medicaid managed care. State Medicaid agencies should include physician satisfaction as a measure of Medicaid managed care plans' quality.

Attitude of Health Personnel↗
PubMed1998

Laser wire for crossing chronic total occlusions: "learning phase" results from the U.S. TOTAL trial. Total Occlusion Trial With Angioplasty by Using a Laser Wire.

The Prima laser guidewire system (Spectranectics Corp., Colorado Springs, CO) consists of an 0.018" hypotube containing a bundle of 45-microm optical fibers coupled to a pulsed excimer laser operating at a tip fluence of 60 ml/mm2 and a repetition rate ranging from 25-40 Hz. This laser guidewire was specifically designed to cross total occlusions refractory to passage with conventional wires. The Prima wire was evaluated in a feasibility study at 15 U.S. centers. Following failure to cross a total occlusion with approved guidewires, the Prima wire was utilized in 179 patients. Average age of subjects was 61 yr. Lesion locations included left anterior descending (36%), right (45%), and circumflex (19%) coronary arteries. Mean angiographic age of total occlusions was 70 wk (range, 2-1,020 wk, median, 14 wk). The use of the Prima wire either solely or in combination with conventional guidewires resulted in successful crossing in 61% of these previously impenetrable occlusions. Failure of the device was commonly related to length of the occlusion and tortuosity along the occluded pathway. Major complications included myocardial infarction in 7 patients (3.9%), tamponade in 3 (1.7%), and death in 2 (1.1%). This "learning phase" pilot study confirmed the feasibility of a laser guidewire in chronic total occlusions that are resistant to passage of conventional guidewires. An extended registry at these investigative sites is planned.

Adult↗
PubMed1998

Effects of ischemic tolerance on mRNA levels of IP3R1, beta-actin, and neuron-specific enolase in hippocampal CA1 area of the gerbil brain.

Global cerebral ischemia induced to Mongolian gerbils by ligation of common carotid arteries (CCAs) is known to result in injury to the hippocampal CA1 region. In this study, we examined whether neuronal injury can be depicted by measuring levels of mRNA encoding inositol 1,4,5-trisphosphate receptor type 1 (IP3R1), neuron specific enolase (NSE) and beta-actin and whether these measurements can be use to assess ischemic tolerance. Gerbils were subjected either to cerebral ischemia induced by ligation of both CCAs for 5 min, or to an ischemic tolerance paradigm in which a 2 min ischemic preconditioning was performed 24 hr prior to the 5 min ischemia. At 48 hr after the 5 min ischemic insult, significant decreases in mRNA levels for IP3R1 (26%), NSE (38%) and beta-actin (50%) could be observed in the hippocampal CA1 region. Although levels of mRNA in the preconditioning group were decreased as compared to the sham control, the levels were significantly higher than those in the ischemic group. These results indicate the feasibility of using mRNA measurement as a parameter to assess cerebral ischemic damage. In addition, based on the differences in the decline in mRNA levels between the ischemia group and the preconditioned ischemia group, it can be concluded that this ischemic tolerance paradigm could offer partial protection (around 45%) against the injury due to the 5 min cerebral ischemic insult.

Actins↗
PubMed1997

Long-term follow-up of kidney donors: a longitudinal study.

BACKGROUND: Kidney donors are not adversely affected by compensatory hyperfiltration of the remaining kidney in the early years after nephrectomy, but longterm longitudinal studies are lacking. METHODS: The renal function and blood pressure of 75 donors was evaluated in 1984, 1.4-20.7 years after surgery. Forty-seven of the original cohort (23 male, age 38-80 years) underwent repeat study a decade later (12-31 years post-nephrectomy), using identical laboratory techniques. RESULTS: Glomerular filtration rates (GFR) as measured by 51Cr EDTA clearance was relatively unchanged a decade later with 41 of 47 subjects (87%) having EDTA clearance within the normal laboratory reference range at review. The change in GFR in the remaining six subjects was statistically not significant. No correlation between GFR and time after nephrectomy was detected. Albumin excretion rate (AER), on timed overnight urine collections, was increased (> 20 micrograms/min) in 16 subjects (34%), although 14 of these individuals were also hypertensive. The prevalence of hypertension was significantly increased compared with age/sex matched data from epidemiological studies of the general population (both in the UK and the US), especially in those over the age of 55 years. CONCLUSION: This study demonstrates that the function of the solitary kidney is not adversely affected by prolonged compensatory hyperfiltration, although there appears to be an increased prevalence of microalbuminuria and hypertension. Regular follow-up of kidney donors is recommended in order to manage their complications effectively and to detect hypertension and or renal impairment early in those who may develop it.

Adult↗
PubMed1996

The effects of taxol, methylprednisolone, and 4-aminopyridine in compressive spinal cord injury: a qualitative experimental study.

BACKGROUND: Taxol is a diterpene alkaloid that stimulates tubulin production in cells. It may be effective in preserving the cytoskeleton of spinal cord axons after injury. METHODS: Thirty-nine rats were submitted to spinal cord compression. The animals were divided into three groups that received taxol (18.75 mg/m2), methylprednisolone (30 mg/kg), or 4-aminopyridine (1 mg/kg). Taxol was administered as one dose immediately after injury and two additional doses on days 14 and 21. Methylprednisolone was given as a single injection immediately postinjury. Four-aminopyridine was administered on days 25, 26, and 27. A group of nine injured animals served as a control without any treatment. Evoked potentials were recorded before, during, and 4 weeks postinjury. Behavioral tests were measured to evaluate recovery of motor function. RESULTS: The taxol and methylprednisolone-treated animals demonstrated a significant improvement in comparison with the control group. No functional improvement was found at 1 mg/kg treatment of 4-aminopyridine in rats. CONCLUSIONS: We conclude that taxol and methylprednisolone given shortly after the compression injury improve functional outcome after an incomplete spinal cord injury.

4-Aminopyridine↗
PubMed1996

Deoxyiminoalditols from aldonolactones--V. Preparation of the four stereoisomers of 1,5-dideoxy-1,5-iminopentitols. Evaluation of these iminopentitols and three 1,5-dideoxy-1,5-iminoheptitols as glycosidase inhibitors.

The four stereoisomeric 1,5-dideoxy-1,5-iminopentitols with D-arabino-(D-lyxo-) (3), ribo- (9), L-lyxo (L-arabino-) (13) and xylo-(18) configurations were synthesized. The corresponding aldonolactones (1, 7 and 11) or aldonic acid ester (15b) having a leaving group at C-5 gave by reaction with aqueous ammonia, the 5-amino-5-deoxy-1,5-lactams, 2, 8, 12 and 17, respectively. Reduction of the lactam function using sodium borohydride/acetic or trifluoroacetic acid, or borane dimethyl sulfide complex yielded the iminopentitols. The compounds 3, 9, 13 and 18, together with the three 1,5-dideoxy-1,5-iminoheptitols 19,20 and 21 were tested for inhibition of the glycosidase activities present in an extract from human liver. Compound 18 was a potent and 19 a moderately good inhibitor of beta-glucosidase. Compound 3 together with 19, 20 and 21, all having D-arabino-configuration at the hydroxy-substituted carbon atoms, were good inhibitors of alpha-L-fucosidase.

Enzyme Inhibitors↗
PubMed1996

Effect of desflurane anesthesia on transcortical motor evoked potentials.

The effect of the volatile anesthetic desflurane on motor evoked potentials was examined in male rats. Animals underwent cortical stimulation using small platinum ball stimulating electrodes secured on the motor cortex. To record evoked compound muscle action potentials (CMAPs), single-shock electrical stimulation was delivered to the forelimb representation of the motor cortex. Muscle responses were readily obtained in the contralateral extensor muscles. The effect of desflurane was examined at various concentrations ranging from 0.7 to 11.4%. With increasing concentrations of desflurane, there was a progressive decrease in the CMAP amplitude and systemic blood pressure over the baseline values. This decrease became statistically significant (p = 0.0078) at 5.7% [1 maximum alveolar concentration (MAC)] concentration of desflurane. Although there was a decrease in heart rate, the results were not statistically significant (p = 0.03). No significant difference in the onset latency or the duration of the CMAP was noted at different concentrations of the anesthetic. We conclude that desflurane anesthesia significantly alters the amplitude of the muscle response evoked by motor cortex stimulation in experimental animals.

Anesthetics, Inhalation↗
PubMed1995

The effect of droperidol on objective markers of patient cooperation and vital signs during esophagogastroduodenoscopy: a randomized, double-blind, placebo-controlled, prospective investigation.

We investigated the effect of droperidol on objective markers of cooperation and vital signs in 140 patients undergoing elective diagnostic esophagogastroduodenoscopy. Procedure duration and the total doses of midazolam and meperidine required during the procedure were evaluated as objective markers of patient cooperation. The droperidol group comprised 66 patients and the placebo group 74 patients. Patient and procedure characteristics were similar for both groups. Droperidol produced a 10% reduction in procedure duration. Linear multiple regression modeling revealed droperidol to be a significant predictor of procedure duration (p = .036). Droperidol significantly reduced midazolam and meperidine requirements (p < .01). Nonetheless, four patients in the droperidol group received naloxone to reverse prolonged, excessive drowsiness. Droperidol produced a significant reduction in procedure-associated increase in pulse rate but did not exacerbate procedure-associated reduction in mean arterial pressure. Droperidol favorably influences markers of patient cooperation during elective, diagnostic esophagogastroduodenoscopy. However, the clinical significance of these changes is unclear.

Adjuvants, Anesthesia↗
PubMed1993

Evaluation of the calcium channel antagonist nimodipine after experimental spinal cord injury.

The cortical somatosensory evoked potentials (CSEPs) were recorded to determine if the administration of nimodipine improves axonal function after spinal cord injury. Animals receiving a 52 g compression injury (a moderately severe injury) for 5 minutes were randomly allocated to one of five treatment groups. Each group was given an infusion of one of the following nimodipine regiments over 2 hours, commencing 1 hour before compression: placebo (n = 20), 0.5 micrograms/kg (n = 10), 0.25 micrograms/kg (n = 20), 0.125 micrograms/kg (n = 10), and 0.25 micrograms/kg + Hetstarch (n = 10). In the control group, 65% of animals lost the CSEPs immediately after the injury with almost all (95%) of these regaining the CSEPs within 15 minutes after decompression of the spinal cord. In the treated groups, the rate of the CSEP loss was highest in the 0.5 micrograms/kg group. This group also had the lowest CSEP recovery. The proportion of the CSEP loss was essentially the same for the other nimodipine-treated groups, although it seemed that there was an increasing number of nonresponses with increasing the nimodipine dose. Our data indicate lack of any beneficial effects of nimodipine on axonal function as measured by evoked activities in experimental spinal cord injury.

Animals↗