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Biomedical subjects

R J Sullivan

Publications and source records attributed to R J Sullivan.

At least 55 records · Page 3Linked to original sources
PubMed1992

Quantitative cerebral anatomy of the aging human brain: a cross-sectional study using magnetic resonance imaging.

Seventy-six healthy adults underwent magnetic resonance imaging (1.5 T) to investigate the effects of age on regional cerebral volumes and on the frequency and severity of cortical atrophy, lateral ventricular enlargement, and subcortical hyperintensity. Increasing age was associated with (1) decreasing volumes of the cerebral hemispheres (0.23% per year), the frontal lobes (0.55% per year), the temporal lobes (0.28% per year), and the amygdala-hippocampal complex (0.30% per year); (2) increasing volumes of the third ventricle (2.8% per year) and the lateral ventricles (3.2% per year); and (3) increasing odds of cortical atrophy (8.9% per year), lateral ventricular enlargement (7.7% per year), and subcortical hyperintensity in the deep white matter (6.3% per year) and the pons (8.1% per year). Many elderly subjects did not exhibit cortical atrophy or lateral ventricular enlargement, however, indicating that such changes are not inevitable consequences of advancing age. These data should provide a useful clinical context within which to interpret changes in regional brain size associated with "abnormal" aging.

Adult↗
PubMed1991

Two-year trends in physical performance following supervised exercise among community-dwelling older veterans.

The extent to which exercise can delay the normal decline in physical performance associated with aging is unknown. We examined the impact of 2 years of supervised exercise on cardiovascular fitness, flexibility, and strength in a group of elderly (age 65-74) veterans. Seventy-five patients exercised 3 days/week for 90-minute sessions emphasizing aerobic, flexibility, and strength development. Thirty-six (47%) completed 2 years of a voluntary supervised exercise program (n = 25 with complete data). Over a 2-year follow-up period, cardiovascular outcome variables improved significantly: metabolic equivalents increased 20% (7.4 +/- 2.2 to 9.0 +/- 2.4, P less than 0.001) and submaximal heart rate decreased 7% (68.5 +/- 8.0 to 63.6 +/- 8.4 beats/minute, P = 0.02). Resting heart rate decreased 8% (131.4 +/- 14.8 to 121.0 +/- 18.5 beats/minute, P = 0.06), but this difference did not reach statistical significance. Flexibility, measured by hamstring length, improved 11% (57.5 +/- 15.1 to 64.0 +/- 11.1 degrees, P = 0.02). Strength variables did not improve. The study indicates that improvements in cardiovascular function and flexibility achieved by the elderly in the early stages of an exercise program can be maintained for at least 2 years.

Aged↗
PubMed1991

Two-year trends in physical performance following supervised exercise among community-dwelling older veterans.

The extent to which exercise can delay the normal decline in physical performance associated with aging is unknown. We examined the impact of 2 years of supervised exercise on cardiovascular fitness, flexibility, and strength in a group of elderly (age 65-74) veterans. Seventy-five patients exercised 3 days/week for 90-minute sessions emphasizing aerobic, flexibility, and strength development. Thirty-six (47%) completed 2 years of a voluntary supervised exercise program (n = 16-25 with complete data). Over a 2-year follow-up period, cardiovascular outcome variables improved significantly: metabolic equivalents increased 20% (7.4 +/- 2.2 to 9.0 +/- 2.4, P less than 0.001) and submaximal heart rate decreased 7% (131.4 +/- 14.8 to 121.0 +/- 18.5 beats/minute, P = 0.06). Resting heart rate decreased 8% (68.5 +/- 8.0 to 63.6 +/- 8.4 beats/minute, P = 0.02) but this difference did not reach statistical significance. Flexibility, measured by hamstring length, improved 11% (57.5 +/- 15.1 to 64.0 +/- 11.1 degrees, P = 0.02). Strength variables did not improve. The study indicates that improvements in cardiovascular function and flexibility achieved by the elderly in the early stages of an exercise program can be maintained for at least 2 years.

Aged↗
PubMed1991

The impact of supervised exercise on the psychological well-being and health status of older veterans.

This study examined the impact of supervised exercise on the health status (measured by the Sickness Impact Profile [SIP]) and well-being (measured by the Psychological General Well-Being Index [PGWB]) of a sample of 43 elderly veterans. The intervention consisted of 90 minutes of exercise, 3 days per week at 70% of maximal capacity. Twenty-three (53%) participants completed a 1-year follow-up. The mean PGWB score increased significantly from 83.0 +/- 15.8 to 89.4 +/- 8.9 (p = .01). Cardiovascular fitness (measured by treadmill performance) increased significantly (p = .004). Baseline SIP scores were low (little dysfunction) and changed little. The study suggests that small but significant improvements in well-being accompany physiological benefits that the elderly experience with exercise.

Aged↗
PubMed1990

Pain clinic #15. Treatment of sciatic nerve causalgia following pelvic fracture.

Direct injury to the sciatic nerve may occur in patients who sustain acetabular/pelvic fractures. Sciatic nerve causalgia has been noted in patients who suffer posterior wall acetabular fracture with or without ipsilateral hip dislocation. Sympathetic nervous system dysfunction is considered the primary cause for this syndrome, although some investigators suggest central nervous system involvement. This report documents the treatment results of three patients suffering from sciatic nerve causalgia who were referred to the Pain Treatment Center during the past year. In each case, diagnosis was confirmed by sympathetic blockade. Treatment regimens varied and included nerve blocks, cryoanalgesia techniques, and transcutaneous electrical nerve stimulation therapy. The syndrome was relieved in these patients within four to six weeks. Patients were followed for six months after initial treatment.

Adolescent↗
PubMed1989

A comparison of interposed abdominal compression CPR and standard CPR by monitoring end-tidal PCO2.

Interposed abdominal compression CPR (IAC-CPR) has been demonstrated to significantly improve blood flow compared with standard (S)-CPR in animal and electrical models. Studies with IAC-CPR in human beings have not reported data regarding cardiac output. Animal and clinical studies have correlated end-tidal PCO2 (ETPCO2) with cardiac output produced with precordial compressions. We conducted a prospective, randomized study on 33 adult patients with nontraumatic cardiac arrest. Patients were randomized to initially receive either S-CPR or IAC-CPR. ETPCO2 was monitored continuously. After 20 minutes of resuscitation, the technique was reversed. The average ETPCO2 during IAC-CPR was 17.1 mm Hg while the average during S-CPR was 9.6 mm Hg, a difference of 78% (P less than .001). In patients arriving in cardiac arrest, return of spontaneous circulation was observed in six patients (30%) during IAC-CPR and in one patient (6%) during S-CPR (P = .07). Our study strongly suggests that cardiac output may be significantly increased in human beings with IAC-CPR as evidenced by the significantly greater increases in ETPCO2 with IAC-CPR compared with S-CPR. In addition, IAC-CPR appeared to demonstrate a trend toward increasing the return of spontaneous circulation.

Abdomen↗
PubMed1989

Evaluation of a supervised exercise program in a geriatric population.

Most studies that assess the effects of exercise in the elderly involve subjects who are in good health. The objective of this prospective longitudinal study was to examine the impact of exercise on cardiovascular fitness, flexibility, and strength in an elderly population that included chronically ill individuals. Patients were recruited initially from a population of veterans over 64 years of age who use a VA outpatient clinic as their regular source of care. The exercise intervention consisted of 90 minutes of exercise 3 days per week at 70% of the patient's maximal capacity. Activities included stationary cycling, stretching, weight training, and walking. Of 69 patients who began the program, 49 (71%) reached 4-month follow-up. Most patients completing follow-up (76%) had at least one chronic disease, such as arthritis, hypertension, or heart disease. Patients who dropped out were more likely to have multiple chronic illnesses than those who remained in the program. Average weekly attendance was 65% and was stable over time. Improvements in cardiovascular fitness at 4-month follow-up were significant: Metabolic equivalents increased from 7.1 +/- 2.3 to 8.3 +/- 2.6 (P less than .001), treadmill time increased from 8.5 +/- 3.8 to 11.2 +/- 4.2 minutes (P less than .001), submaximal heart rate decreased from 123.7 +/- 18.8 to 118.8 +/- 19.4 beats per minute (P less than .001) and resting heart rate decreased from 68.1 +/- 10.6 to 63.3 +/- 11.6 beats per minute (P = .005).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

The copper sites of dopamine beta-hydroxylase: an X-ray absorption spectroscopic study.

X-ray absorption edge and extended X-ray absorption fine structure (EXAFS) spectra are reported for the Cu(I) and Cu(II) forms of bovine dopamine beta-hydroxylase (DBH; EC 1.14.17.1) and for the Cu(I) form of DBH bound either to tyramine substrate or to a multisubstrate inhibitor [Kruse, L. I., DeWolf, W. E., Jr., Chambers, P. A., & Goodhart, P. J. (1986) Biochemistry 25, 7271-7278]. A significant change in the structure of the copper sites occurs upon ascorbate-mediated reduction of Cu(II) DBH to the Cu(I) form. While the average Cu(II) site most likely consists of a square-planar array of four (N,O)-containing ligands at 1.98 A, the average Cu(I) site shows a reduction in (N,O) coordination number (from approximately 4 to approximately 2) and the addition of a S-containing ligand at 2.30 A. No change in the average Cu(I) ligand environment accompanies binding of tyramine substrate, whereas binding of a multisubstrate inhibitor, 1-(3,5-difluoro-4-hydroxybenzyl)-1H-imidazole-2(3H)-thione, causes an increase in the Cu-S coordination, consistent with inhibitor binding to the Cu(I) site through the S atom. Although excellent signal-to-noise ratio in the EXAFS spectra of ascorbate-reduced DBH facilitated analysis of outer-shell scattering for a Cu..Cu interaction, the presence of a binuclear site could not be proven or disproven due to interference from Cu...C scattering involving the carbons of imidazole ligands.

Adrenal Medulla↗
PubMed1987

Extended X-ray absorption fine structure of copper in CuA-depleted, p-(hydroxymercuri)benzoate-modified, and native cytochrome c oxidase.

Cytochrome c oxidase contains four redox-active metal centers: two heme irons, cytochromes a and a3, and two copper ions, CuA and CuB. Due to the paucity of spectroscopic signatures for both copper sites in cytochrome c oxidase, the ligands and structures for these sites have remained ambiguous. The specific depletion of CuA from the p-(hydroxymercuri)benzoate- (pHMB-) modified cytochrome c oxidase recently reported [Gelles, J., & Chan, S. I. (1985) Biochemistry 24, 3963-3972] is herein described. Characterization of this enzyme shows that the structures of the remaining metal centers are essentially unperturbed by the CuA modification and depletion (P. M. Li, J. Gelles, and S. I. Chan, unpublished results). Copper extended X-ray absorption fine structure (EXAFS) measurements on the CuA-depleted cytochrome c oxidase reveal coordination of three (N, O) ligands and one (S, Cl) ligand at the CuB site. Comparison of EXAFS results obtained for the CuA-depleted, pHMB-modified, and "unmodified control" enzymes has allowed the deconvolution of the EXAFS in terms of the inner coordination spheres for CuA as well as CuB. On the basis of these data, it is found that the structure for the CuA site is consistent with two (N, O) ligands and two S ligands.

Copper↗
PubMed1986

On-call: now, and then.

Explore the source record for details and available documents.

Health Maintenance Organizations↗
PubMed1982

Factors related to an effective referral and consultation process.

A study of 141 consecutive referrals from family physicians in four clinic sites was undertaken to obtain descriptive characteristics of the referral-consultation process and to identify factors associated with effective outcomes. Consultation reports were returned to referring physicians in 88 percent, 75 percent, and 43 percent of referrals from consultants in community practice, university faculty practice, and university outpatient clinics, respectively. The quality of the consultation reports, as determined by the referring physician's opinion, increased directly with the amount of referral information originally sent to the consultant. The referral-consultation process appears to be functioning well in this site. The data suggest that this process might function even better if referring physicians would personally contact and send letters to consultants.

Communication↗