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Biomedical subjects

R L Vogel

Publications and source records attributed to R L Vogel.

At least 19 recordsLinked to original sources
PubMed1998

Multivariate analysis of factors associated with postoperative pulmonary complications following general elective surgery.

OBJECTIVE: To develop a predictive model identifying perioperative conditions associated with postoperative pulmonary complications (PPCs). DESIGN: A prospective survey of patients whose preoperative history and physical examination, spirometric, PaO2 and PaCO2 analysis, and operative results were recorded. These patients underwent postoperative cardiopulmonary examinations until they were discharged from the hospital; their medical records were also reviewed until they were discharged from the hospital. SETTING: The Louisville Veterans Administration Medical Center, Louisville, Ky. PATIENTS: A randomly chosen sample of patients aged 40 years or older who required elective, nonthoracic surgery under general or spinal anesthesia and who were hospitalized at least 24 hours postoperatively. MAIN OUTCOME MEASURE: An analysis of risk factors associated with the development of 1 or more of the following conditions: acute bronchitis, bronchospasm, atelectasis, pneumonia, adult respiratory distress syndrome, pleural effusion, pneumothorax, prolonged mechanical ventilation, or death secondary to acute respiratory failure. RESULTS: Postoperative pulmonary complications developed in 16 (11%) of 148 patients. The risk factors found to be higher among those with PPCs compared with those without PPCs were postoperative nasogastric intubation (81% vs 16%, P<.001), preoperative sputum production (56% vs 21%, P=.005), and longer anesthesia duration (480 vs 309 minutes, P<.001). Upper abdominal surgery was performed in 11 (69%) of the 16 patients with PPCs and in 20 (15%) of the 132 patients without PPCs (P<.001); this difference lost significance in multivariate analysis. The final linear logistic model included postoperative nasogastric intubation (odds ratio [OR], 21.8), preoperative sputum production (OR, 4.6), and longer anesthesia duration (OR exp[0.01x] for an increase in x minutes) (1 minute of additional anesthesia time increases the OR to 1.01), resulting in 92% accuracy in predicting PPCs. CONCLUSIONS: We identified 3 potentially modifiable risk factors for PPCs. If validated, our results may lead to modifications of perioperative care that will further reduce PPCs.

Adult↗
PubMed1998

Emergency department use by nursing home residents.

STUDY OBJECTIVE: To describe a community's experience with the use of emergency department services by nursing home residents. METHODS: We performed a retrospective chart review of a population-based cohort of nursing home residents in an urban county in central Georgia with 10 nursing homes (1,300 beds) and 4 hospital-based EDs. All ED visits by nursing home residents during 1995 were analyzed. Demographic data, timing of the visit, chief complaint, tests and treatments, disposition, and financial charges were recorded. Further, we calculated the number of ED visits per 100 nursing home patient-years. RESULTS: A total of 873 nursing home residents made 1,488 ED visits. Mean age was 76.0 years; 66.4% were female, and 55.2% were white. Of the transfers, 42.9% occurred during regular working hours. The most common chief complaints were respiratory symptoms (14.4%), altered mental status (10.1%), gastrointestinal symptoms (9.9%), and falls (8.2%); 101 patients (6.8%) were transferred for malfunction of a gastrostomy tube. The most common laboratory tests were complete blood cell count (69.5%), chest radiograph (52.0%), electrocardiogram (45.0%), urinalysis (42.7%), and determination of electrolytes (42.7%). A total of 42.4% of the ED visits led to admission to the hospital. From the 10 nursing homes, there were 110 ED visits per 100 patient-years. A 3.5-fold difference in ED use among these nursing homes could not be explained by age, gender, or other factors. The average .charge per ED visit was $1,239. CONCLUSION: Elders living in nursing homes are frequently transferred to EDs for costly medical evaluations, and more than 40% of such visits lead to admission to the hospital.

Aged↗
PubMed1998

High fatty acid content in rabbit serum is responsible for the differentiation of osteoblasts into adipocyte-like cells.

Osteoblasts and adipocytes originate from common mesenchymal precursors. With aging, there is a decrease in osteoprogenitor cells that parallels an increase of adipocytes in bone marrow. We observed that rabbit serum (RS) induces adipocyte-like differentiation in human osteosarcoma SaOS-2/B10 and MG-63 cell lines, in rat ROS17/2.8 cells, and in mouse calvaria-derived osteoblastic MB1.8 cells, as evidenced by the accumulation of Oil Red O positive lipid vesicles and the decrease in alkaline phosphatase expression. Both SaOS-2/B10 and MG-63 cells, but not ROS17/2.8 nor MB1.8 cells, express significant levels of PPARgamma mRNA, a member of the peroxisome proliferator activated receptor (PPAR) family that has been implicated in the control of adipocyte differentiation. However, both ROS17/2.8 and MG-63 cells express significant levels of the adipocyte selective marker, aP2 fatty acid binding mRNA, which can be further increased by RS. These cell types express PPARdelta/NUC-1 but not PPARalpha, indicating that cells that do not express either PPARgamma or PPARalpha are capable of differentiating into adipocyte-like cells. Transfection experiments in COS cells showed that compared with fetal bovine serum (FBS), RS is rich in agents that stimulate PPAR-dependent transcription. The stimulatory activity was ethyl acetate extractable and was 35-fold more abundant in RS than in FBS. Purification and analysis revealed that the major components of this extract are free fatty acids. Furthermore, the same fatty acids, a mixture of palmitic, oleic, and linoleic acids, activate the PPARs and induce adipocyte-like differentiation of both ROS17/2.8 and SaOS-2/B10 cells. These findings suggest that fatty acids or their metabolites can initiate the switch from osteoblasts to adipocyte-like cells.

Adipocytes↗
PubMed1998

Is primary care physician supply correlated with health outcomes?

Assessment of the relation between life indicators and health outcomes is a complex problem. The authors' analysis uses descriptive canonical correlation, and their solution suggests that socioeconomic factors play a major role in health outcomes. The supply of primary care physicians has a lesser but still important role: canonical correlation suggests no apparent role in enhancing health outcomes among the elderly but a larger role in improving health among the young. The authors' analysis does support the notion that specialist physician supply has no correlation with a wide range of health outcomes.

Adult↗
PubMed1998

Esophagogastroduodenoscopy performed by a family physician. A case series of 793 procedures.

BACKGROUND: Primary care physicians are performing an increasing number of gastrointestinal endoscopies. The purpose of this research is to present a large case series of diagnostic esophagogastroduodenoscopies (EGDs) performed by a family physician in a solo rural practice. METHODS: We present a retrospective chart review, including demographic characteristics, indications, endoscopic and pathologic findings, and complications for every EGD performed by a family physician over a 7-year period. RESULTS: Seven hundred ninety-three EGDs were performed on 602 patients (421 women, 181 men), with a mean age of 51.8 years. In 99% of procedures, the second portion of the duodenum was intubated. The most common indications for EGD were abdominal pain (60.5%), gastrointestinal bleeding (23.0%), dysphagia (11.6%), and heart-burn (10.7%). A total of 451 biopsies were obtained in 385 procedures, mostly from the distal esophagus (38%) or gastric antrum (37%). Common endoscopic diagnoses were gastritis (54%), esophagitis (25%), and normal study (15%). There were only two malignancies detected, one gastric lymphoma and one carcinoma metastatic to the stomach. One minor complication (0.13%) occurred, an immediate urticarial rash after intravenous meperidine. CONCLUSIONS: Experienced family physicians can safely and competently perform diagnostic EGD and provide this important service to their community.

Adolescent↗
PubMed1997

Comparison of parametric and non-parametric survival methods using simulated clinical data.

We derived three parametric survival models (the log-normal, log logit, and Weibull) from the clinical data of chemotherapy trials for stage II breast cancer. We then used these models to generate simulated survival data, which we analysed using both parametric (log-normal) and non-parametric (logrank, Gray-Tsiatis and Laska-Meisner) methods. With limited follow-up (5 years), the non-parametric tests had greater power than the log-normal model. This advantage diminished, however, with extended follow-up (15 years). Furthermore, only the log-normal model could distinguish reliably a survival advantage due to an increase in cured fraction from an advantage due to an increase in time to failure.

Breast Neoplasms↗
PubMed1997

The effects of isoproterenol on the cardiac conduction system: site-specific dose dependence.

INTRODUCTION: Isoproterenol is used to assess and facilitate AV nodal conduction, and thus potentiate the induction of supraventricular arrhythmias. It is commonly administered in increasing doses until a predetermined decrease in sinus cycle length, usually 20% to 30%, occurs. This regimen may result in undesirable side effects. We have observed that effects of isoproterenol on the AV node may occur prior to achieving the target sinus cycle length. The purpose of this study was to determine whether the sinus and AV nodes have equal sensitivity to isoproterenol. METHODS AND RESULTS: Thirty-eight consecutive patients, who underwent electrophysiologic evaluation for a variety of indications, were given incremental doses of isoproterenol at 0.007, 0.014, 0.021, and 0.028 microgram/kg per minute. Sinus cycle length and AV node function were assessed at baseline and after 5 minutes at each dose. The percent change from baseline in AV node function was compared with the change in sinus cycle length at each dose interval. Significantly greater decreases were observed in the anterograde and retrograde AV nodal Wenckebach cycle length (P < 0.0001) than in the sinus cycle length at the lowest isoproterenol dose (0.007 microgram/kg per min). These differences were not apparent at higher doses. A sustained supraventricular tachycardia was inducible in 15 of 38 patients in the presence of isoproterenol, of which 40% occurred at the lowest dose. CONCLUSIONS: The AV node is more sensitive than the sinus node to the effects of isoproterenol. Lower doses of isoproterenol than those commonly used may often facilitate the induction of a supraventricular tachyarrhythmia, thus reducing side effects.

Adult↗
PubMed1997

Colonoscopy performed by a family physician. A case series of 751 procedures.

BACKGROUND: Colonoscopy, including biopsy and polypectomy, is a procedure not commonly performed by primary care physicians. The purpose of this research was to present a large case series of colonoscopic procedures performed by a family physician in a rural practice. METHODS: A chart review of every colonoscopy procedure performed by a family physician over a 7-year period determined the demographic characteristics, indications, findings, and complications for each procedure. RESULTS: A total of 751 colonoscopies were performed on 555 patients (347 women and 208 men), with a mean age of 53.8 years. In 91.5% of procedures, the cecum was intubated. The most common indications for colonoscopy were bleeding (49.9%), polyp follow-up (20.9%) abdominal pain (11.7%), diarrhea (11.6%), and abnormal findings on flexible sigmoidoscopy (8.4%). Three hundred sixteen benign polyps were discovered and removed by either biopsy or polypectomy. There were 184 adenomatous colorectal polyps found in 134 (17.8%) colonoscopies. Of these 184 adenomatous polyps, 106 (58%) were potentially within reach of the flexible sigmoidoscope. Only three adenocarcinomas were discovered during the entire study period. There was only one major procedural complication: a patient experienced blood oozing from a polypectomy stump; cautery stopped the bleeding, and the patient was hospitalized overnight, with no further intervention or transfusion required. There were five other self-limited complications, including adverse reactions to sedation and infiltration at the intravenous site. CONCLUSIONS: Colonoscopy with polypectomy that was safely and competently performed in a solo rural practice adds to the evidence that experienced family physicians can provide this important service to their community.

Adenocarcinoma↗
PubMed1996

Identification of fatty acid methyl ester as naturally occurring transcriptional regulators of the members of the peroxisome proliferator-activated receptor family.

The nuclear hormone receptors NUC-1 (PPAR delta) and PPAR alpha are members of the peroxisome proliferator-activated receptor (PPAR) family. The members of this receptor family are activated by agents that stimulate peroxisome proliferation, free fatty acids, prostaglandin 12 metabolites, and agents considered for the therapy of insulin-independent diabetes mellitus. To identify putative physiological agents that activate NUC-1, we tested the ability of acetone extracts of various rat tissues to activate the transcription of an MMTV-luciferase reporter gene, via a GR/NUC-1 hybrid receptor. GR/NUC-1 contains the ligand binding region of the NUC-1 receptor and the DNA binding domain of the glucocorticoid receptor. Using this assay, we found stimulatory activity in the pancreas, which upon purification and characterization was identified as methyl-palmitate, known to be enriched in pancreatic lipids. In addition, we determined that ethyl esters of palmitic and oleic acids are also potent activators of this receptor. Thus, fatty acid ester formation may control the cellular concentrations of fatty acids, and acyl-ester formation may play a role in the control of metabolic pathways and the activation of the PPAR.

Animals↗
PubMed1996

Primary ablation of atrial flutter and atrial fibrillation.

Direct treatment of atrial flutter and atrial fibrillation--that is, attempting to prevent arrhythmia recurrences by ablating atrial tissue--has been a challenge because of uncertainty about the location of optimal target tissues as well as the amount of atrial tissue requiring destruction to effect cure. Advances have yielded success rates for ablation of the common form of atrial flutter comparable to those for other types of supraventricular tachycardia and provide reason for optimism about the use of catheter techniques, to treat atrial fibrillation definitively. This article discusses some of these advances as well as the current status of catheter ablation for atrial flutter and atrial fibrillation and, finally, what the future may bring.

Animals↗
PubMed1996

P2 flash visual evoked response delay may be a marker of cognitive dysfunction in healthy elderly volunteers.

In an earlier study, 31 healthy elderly volunteers had normal cognitive function as measured by the Mini-Mental State Examination. Twenty-seven returned for further memory testing using the Wechsler Memory Scale-Revised (WMS-R). The P2 latency of the flash visual evoked response was positively correlated with age (p = .0008), but was not significantly related to gender. Nine of these 27 putatively healthy subjects had a delayed P2, suggestive of dementia. Although unaware of any memory deficits, 5 of the 27 had WMS-R Visual Memory Span percentile scores 1 or more standard deviations less than age-matched controls. Four of the five also had a significantly delayed P2 component. This positive correlation, adjusted for age, between poor Visual Memory Span performance and a delayed P2 was statistically significant (p < .025). These findings suggest that a delayed P2 in putatively healthy subjects is indicative of a visuospatial deficit which might be a precursor of dementia later.

Aged↗
PubMed1995

Oral terbutaline in the outpatient management of preterm labor.

OBJECTIVE: Our purpose was to prove our hypothesis that once preterm uterine contractions and/or labor is controlled with intravenous tocolysis, oral terbutaline, as a maintenance drug, does not prolong pregnancy. STUDY DESIGN: Before discharge, 184 patients between 24 and 35 completed weeks' gestation were prospectively randomized to continued bed rest either with or without oral terbutaline. Assignment was made with stratification into four groups: group 1, those patients with a Bishop score > or = 5 with oral terbutaline (n = 50); group 2, those with a Bishop score > or = 5 without oral terbutaline (n = 53); group 3, those with a Bishop score < 5 with oral terbutaline (n = 41); group 4, those with a Bishop score < 5 without oral terbutaline (n = 40). Oral terbutaline was discontinued at 37 completed weeks. RESULTS: No statistically significant differences were found in the number of readmissions, the number of unscheduled hospital visits, and the neonatal outcomes among the four groups. The gestational age at delivery and percent of deliveries at > or = 37 weeks were not significantly different when group 1 was compared with group 2 and group 3 was compared with group 4. CONCLUSION: Oral terbutaline maintenance does not improve pregnancy outcome in patients who have had initial successful intravenous tocolysis.

Administration, Oral↗
PubMed1995

Surgery in nonagenarians: morbidity, mortality, and functional outcome.

BACKGROUND: There are few studies that document the outcomes experienced by very old patients who undergo major surgery. METHODS: This is a case series and 7-year follow-up of 116 consecutive patients who were aged 90 years or older and underwent major surgery at a large university-affiliated community hospital. We describe the functional status, short- and long-term mortality, and predictors of mortality in this group of frail elders. RESULTS: The 116 nonagenarians in this study underwent 134 major operations. Sixty-three patients were admitted to the hospital from a nursing home. The most common surgical procedures were for hip fracture, lower extremity amputation, and abdominal problems. Nineteen patients died in the hospital following surgery, and 23 patients died within 30 days of operation. Follow-up at 7 years revealed that all but three patients had died. Survival was worse for patients admitted from nursing homes, those who were nonambulatory before surgery, and those with major or complete functional impairment. CONCLUSIONS: Major surgery in nonagenarians is associated with a 20% perioperative mortality. Functional status and ambulatory ability are maintained in most patients. Whether to operate on these frail elders is a complex decision.

Aged↗
PubMed1994

Parametric survival analysis of adjuvant therapy for stage II breast cancer.

BACKGROUND: Standard, nonparametric statistical methods estimate only the impact of therapy on survival rate up to a selected follow-up interval. In contrast, parametric methods can estimate the impact of treatment on the two cardinal parameters of malignancy: likelihood of cure and recurrence free survival time among uncured patients. METHODS: The authors screened a total of six parametric survival models. Three of these, including the log normal model, were applied to survival data from five clinical trials of adjuvant therapy for Stage II breast cancer. For comparison, the log rank test, a standard nonparametric method, was also applied to the same data. RESULTS: Both parametric and nonparametric methods identified a significant therapeutic in three of the five trials. In only one of these three trials, however, did parametric analysis identify a significant difference in the likelihood of cure between treatment groups. In the remaining two trials, a significant difference was found in recurrence free survival time among uncured patients. The three parametric survival models gave similar results. CONCLUSION: These findings suggest that parametric analysis may warrant further study as a method for measuring the long term clinical impact of adjuvant therapy on Stage II breast cancer.

Breast Neoplasms↗
PubMed1994

Helicobacter pylori is associated with alterations in intestinal gas profile among patients with nonulcer dyspepsia.

The pathogenesis of nonulcer dyspepsia (NUD) is unknown. Gas and postprandial bloating are frequent symptoms. The role of Helicobacter pylori (HP) in the pathogenesis of NUD is controversial. We studied the intestinal gas profile of NUD patients (N = 34) at baseline and after lactulose administration. The prevalence of hydrogen and methane producers was similar among HP+ and HP- patients. Breath H2 concentrations in response to lactulose showed significantly greater rise among HP+ subjects (P < 0.0001). HP positivity was associated with higher total breath excretion for H2 and methane combined (2984 +/- 1038 vs 1776 +/- 521 ppm/hr) compared to HP- subjects (P < 0.05). There was no correlation between peak H2 and methane levels. The role of alterations in intestinal gas in producing symptoms in HP+ patients with NUD needs further investigation.

Adult↗
PubMed1994

Dobutamine two-dimensional transesophageal echocardiographic stress testing for detection of coronary artery disease.

Atrial pacing and dipyridamole transesophageal echocardiography have been shown to be sensitive and specific tests for the detection of coronary artery disease. However, the sensitivity and specificity of dobutamine transesophageal echocardiography have not been reported. The purpose of this study was to determine the feasibility, sensitivity, and specificity of dobutamine transesophageal echocardiography for the detection of coronary artery disease. Transesophageal echocardiographic assessment of left ventricular function was performed in 81 adult patients aged 62 +/- 12 years during stepwise infusion of dobutamine from 5.0 to 40 micrograms/kg/min. Ischemia was diagnosed by the development of severe hypokinesis, akinesis, or dyskinesis of a previously contractile left ventricular segment. Coronary artery disease was defined by angiography as a reduction in luminal diameter of > or = 70% of an epicardial or > or = 50% of the left main coronary artery. In patients who had undergone coronary artery bypass graft surgery, a stenotic bypass graft was defined as a reduction in luminal diameter of > or = 70%. In patients without previous CABG, significant coronary artery disease was present in 21 patients: 5 with single-vessel disease, 7 double-vessel disease, 8 triple-vessel disease, and 1 left main coronary disease. Dobutamine transesophageal echocardiography had a sensitivity of 90% (19 of 21) and specificity of 94% (49 of 52) for the detection of coronary artery disease. In patients with previous CABG (n = 8), the sensitivity and specificity for the detection of bypass graft stenosis were 100% (4 of 4) and 75% (3 of 4), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗