PubMed Health⌕ Search

Biomedical subjects

R Burns

Publications and source records attributed to R Burns.

15 recordsLinked to original sources
PubMed1992

Primary mutations in calmodulin prevent activation of the Ca(++)-dependent Na+ channel in Paramecium.

Paramecium tetraurelia behavioral mutant cam12 displays a "fast-2" behavioral phenotype: it fails to respond to Na+ stimuli. Electrophysiologically, it lacks a Ca(++)-dependent Na+ current. Genetics and DNA sequencing showed the primary defect of cam12 to be in the calmodulin gene (Kink et al., 1990). To correlate calmodulin structure and function in Paramecium, we elucidated the primary structure of cam12 calmodulin. Peptide sequencing confirmed the two point mutations predicted by the DNA sequence: a glycine-to-glutamate substitution at position 40 and an aspartate-to-asparagine substitution at position 50. Our results further showed that lysine 13 and lysine 115 were methylated normally in cam12. It is likely that the electrophysiological abnormalities of cam12 are a direct reflection of the amino-acid substitutions, as opposed to improper posttranslational modification.

Amino Acid Sequence↗
PubMed1992

Decrease of depression during stroke and amputation rehabilitation.

Clinical observation had suggested that mild depression occurs after admission for acute medical treatment and then decreases during further hospitalization for rehabilitation treatment. The Geriatric Depression Scale (GDS) was given on admission and discharge to 14 stroke and 17 amputee rehabilitation patients. Each of the two groups showed decreasing GDS scores from beginning to end of the rehabilitation admission. Suggested reasons included: (1) the gradually diminishing effects of stroke and amputation as life crises during the 1-2 month admission, (2) effects of physical improvement on mood and affect, (3) milieu effects of the medical ward, and (4) tendencies for all psychopathology scale scores to decrease on retest.

Activities of Daily Living↗
PubMed1992

Increase of medical hospital length of stay by depression in stroke and amputation patients: a pilot study.

Past studies have found that medical patients with the diagnosis of depression (comorbidity) have longer hospital lengths of stay (LOS) than those without the diagnosis of depression. This suggested that scores on a depression scale would be positively correlated with LOS. On a rehabilitation ward, 14 stroke and 17 amputee patients were given the Geriatric Depression Scale (GDS) and lengths of stay were recorded. Correlations between GDS scores and LOS were +0.575 for stroke and +0.266 for amputee patients, both in the hypothesized direction. Explanations considered included: (1) depression and medical illness each produce morbidity which summate to require increased LOS; (2) depression delays medical recovery as well as the appearance of medical recovery, and (3) discharge planning is complicated by depression. When depression is associated with inpatient medical illness, DRGs may need to be reevaluated.

Activities of Daily Living↗
PubMed1991

The stop/glide boundary shift: modelling perceptual data.

Research in speech perception has suggested that listeners often adjust category boundary locations for differing contexts. The stop/glide (e.g.,/ba/vs./wa/) boundary shift occurring with changes in syllable duration has been interpreted as reflecting 'rate normalization' by some, whereas others have suggested an auditory basis for the shift. Clarification of both the causes and the effects of the stop/glide shift is being sought through experimentation intended to expand our knowledge of variations in the shift across different experimental treatments. The present study extends research on the stop/glide shift by (1) showing that the shift is not an artifact of a particular stimulus pattern that had been present in all the previous studies of the effect, (2) further demonstrating the nonlinear character of the identification shift, (3) providing additional evidence of the role of presentation format (mixed vs. blocked) in the identification shift, and (4) exploring boundary locations in various discrimination paradigms. The complex outcomes of the studies reported here as well as a variety of previous results are interpreted as compatible with expanded versions of the durational contrast hypothesis. Two versions are considered, one in which the shift is seen as due to a mechanism of contrastive perception that applies to events of comparable duration, and one in which the shift is seen as a perceptual error that occurs when the auditory system attempts to track frequency trajectories that change (i.e., pivot) over time.

Adult↗
PubMed1979

Cerebrovascular disease.

Cerebrovascular disorders producing transient or permanent symptoms and signs are very common, but they are not the only causes of a sudden neurologic deficit. Careful examination of the cardiovascular system may indicate the likely cause of the lesion, while accurate neurologic localization is also useful in establishing a diagnosis and prognosis. The CT scan is very helpful in distinguishing infarction from haemorrhage. In the management of the acute lesion, treatable disorders such as systemic diseases, potentially fatal rostro-caudal herniation, haematomas and aneurysms always need to be positively exlcuded. Endarterectomy, platelet inhibitors and anticoagulants are advised in certain situations, although their place in the management of cerebrovascular disorders still remains somewhat controversial.

Auscultation↗
PubMed1978

Jaundice associated with polycystic liver disease.

Jaundice is rarely encountered in polycystic disease of the liver. In the present case, pressure from tense cysts at the hilus of the liver caused a marked narrowing of the common hepatic duct and slowing of bile flow with the formation of stasis stones. Decompression of the cysts and removal of debris in the intrahepatic ducts resulted in a rapid decrease of the serum bilirubin level.

Bilirubin↗
PubMed1978

Hypercalciuria related to cadmium exposure.

A work force has been investigated for possible cadmium intoxication. One group who are coppersmiths have an 18.5 per cent prevalence of upper urinary tract stone disease associated with a statistically highly significant hypercalciuria and reduced serum inorganic phosphate. Proof of exposure to cadmium has been confirmed in all workers. The trace element cadmium should be kept in mind when investigating stone formers who exhibit an unexplained hypercalciuria.

Cadmium↗
PubMed1975

Systemic heparinization during percutaneous coronary angiography: evaluation of effectiveness in decreasing thrombotic and embolic catheter complications.

Systemic heparinization has been advocated as preventive for thrombotic and embolic complications of arterial catheterization. To test this hypothesis, 95 patients undergoing coronary angiography via the percutaneous femoral arterial approach were randomized into heparinized and nonheparinized groups. Evaluation for thrombotic and embolic complications by clinical means and non-invasive electrical impedance flow measurements in the lower limbs was performed precatheterization, postcatherization, and at 4 and 24 hr. Clinical data reveal loss of distal leg pulses in 11% (5/74) of the nonheparinized group, with two of these individuals developing signs of claudication and requiring embolectomy. No individuals (0/48) in the heparinized group lost distal leg pulses. Immediate, 4-hr, and 24-hr post-catheterization bloodflow was 12%, 10%, and 12% lower, respectively, in the catheterized limb of those in the nonheparinized group. At 24 hr 52% of the nonheparinized group had bloodflow levels lower than the precatheterization levels in the right (catheterized) extremity, while 2% (2/48) of the heparinized group had a similar reduction. One possible complication of excess bleeding was noted with heparin. It is concluded that systemic heparinization is safe and can be an important adjunct in the reduction of thromboembolic complications of percutaneous coronary angiography.

Angiocardiography↗
PubMedDate not supplied

Factors predicting readmission of older general medicine patients.

OBJECTIVES: 1) Identify demographic, clinical social support, functional, and psychological factors about which data are available within 24 hours of hospital admission associated with emergent unscheduled readmission for a group of older general medicine patients; 2) develop a model to predict emergent readmission. DESIGN: Interview- and chart-based study of emergent admissions that occurred within 60 days of discharge. SETTING: General medicine wards of the Memphis Veterans Affairs Medical Center, an 862-bed university-affiliated tertiary care facility. PATIENTS/PARTICIPANTS: General medicine patients greater than or equal to 65 years old (n = 173). Inclusion criteria were willingness to participate, written consent (patient or family member), and patient interview within 36 hours of admission. MEASUREMENTS AND MAIN RESULTS: The dependent variable was emergent readmission within 60 days of discharge from the hospital. Independent variables included demographic (age, race, income, education), social support (marital status, living arrangements), psychological (cognition, depression), activities of daily living functioning, and clinical (diagnoses, type and source of admission, length of stay, numbers of hospitalizations and days of hospitalizations in the past year, illness severity) parameters. Readmitted patients were emergently admitted and more severely ill, had more diagnoses of chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF), less ischemic heart disease, and more hospitalizations and hospital days in the past year (all p less than 0.05). Logistic regression identified diagnostic group (COPD or CHF), emergent admission, and admission severity of illness as predictive of readmission. The likelihood of being readmitted was 5.4. Accuracy of the three-variable model was 76%, predicted value positive, 73%, and predictive value negative, 77%. CONCLUSIONS: Chronically ill patients who are severely ill at index admission and who have had several hospitalizations in the past year tend to be readmitted. Using this model, high-risk patients may be prospectively targeted to reduce readmissions.

Aged↗