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Biomedical subjects

M J Sullivan

Publications and source records attributed to M J Sullivan.

At least 91 records · Page 5Linked to original sources
PubMed1991

Dynamic regulation of leg vasomotor tone in patients with chronic heart failure.

We examined the central hemodynamic (n = 5) and leg blood flow (n = 9) responses to one- and two-leg bicycle exercise in nine ambulatory patients with chronic heart failure due to left ventricular systolic dysfunction (ejection fraction 17 +/- 9%). During peak one- vs. two-leg exercise, leg blood flow (thermodilution) tended to be higher (1.99 +/- 0.91 vs. 1.67 +/- 0.91 l/min, P = 0.07), whereas femoral arteriovenous oxygen difference was lower (13.6 +/- 3.1 vs. 15.0 +/- 2.9 ml/dl, P less than 0.01). Comparison of data from exercise stages matched for single-leg work rate during one- vs. two-leg exercise demonstrated that cardiac output was similar while both oxygen consumption and central arteriovenous oxygen differences were lower, indicating relative improvement in the cardiac output response at a given single-leg work rate during one-leg exercise. This was accompanied by higher leg blood flow (1.56 +/- 0.76 vs. 1.83 +/- 0.72 l/min, P = 0.02) and a tendency for leg vascular resistance to be lower (92 +/- 54 vs. 80 +/- 48 Torr.l-1.min, P = 0.08) without any change in blood lactate. These data indicate that, in patients with chronic heart failure, leg vasomotor tone is dynamically regulated, independent of skeletal muscle metabolism, and is not determined solely by intrinsic abnormalities in skeletal muscle vasodilator capacity. Our results suggest that relative improvements in central cardiac function may lead to a reflex release of skeletal muscle vasoconstrictor tone in this disorder.

Aged↗
PubMed1991

Altered skeletal muscle metabolic response to exercise in chronic heart failure. Relation to skeletal muscle aerobic enzyme activity.

BACKGROUND: Exertional fatigue, which frequently limits exercise in patients with chronic heart failure, is associated with early anaerobic metabolism in skeletal muscle. The present study was designed to examine the skeletal muscle metabolic response to exercise in this disorder and determine the relation of reduced muscle blood flow and skeletal muscle biochemistry and histology to the early onset of anaerobic metabolism in patients. METHODS AND RESULTS: We evaluated leg blood flow, blood lactate, and skeletal muscle metabolic responses (by vastus lateralis biopsies) during upright bicycle exercise in 11 patients with chronic heart failure (ejection fraction 21 +/- 8%) and nine normal subjects. In patients compared to normal subjects, peak exercise oxygen consumption was decreased (13.0 +/- 3.3 ml/kg/min versus 30.2 +/- 8.6 ml/kg/min, p less than 0.01), whereas peak respiratory exchange ratio and femoral venous oxygen content were not different (both p greater than 0.25), indicating comparable exercise end points. At rest in patients versus normals, there was a reduction in the activity of hexokinase (p = 0.08), citrate synthetase (p less than 0.02), succinate dehydrogenase (p = 0.0007), and 3-hydroxyacyl CoA dehydrogenase (p = 0.04). In patients, leg blood flow was decreased at rest, submaximal, and maximal exercise when compared to normal subjects (all p less than 0.05), and blood lactate accumulation was accelerated. In patients, during submaximal exercise blood lactate levels were not closely related to leg blood flow but were inversely related to rest citrate synthetase activity in skeletal muscle (r = -0.74, p less than 0.05). At peak exercise there were no intergroup differences in skeletal muscle glycolytic intermediates, adenosine nucleotides, or glycogen, whereas in patients compared to normal subjects less lactate accumulation and phosphocreatine depletion were noted (both p less than 0.05), suggesting that factors other than the magnitude of phosphocreatine depletion or lactate accumulation may influence skeletal muscle fatigue in this disorder. CONCLUSIONS: The results of the present study suggest that in patients with chronic heart failure reduced aerobic activity in skeletal muscle plays an important role in mediating the early onset of anaerobic metabolism during exercise. Our findings are consistent with the concept that reduced aerobic enzyme activity in skeletal muscle is, in part, responsible for determining exercise tolerance and possibly the response to chronic intervention in patients with chronic heart failure.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1991

Arytenoid subluxation: diagnosis and treatment.

Both arytenoid subluxation and recurrent laryngeal nerve paralysis (RLNP) may result from injury to the larynx, and they may be difficult to distinguish clinically. A patient with arytenoid subluxation who was initially believed to have RLNP was treated with medialization laryngoplasty 1 year after the injury. Preoperative magnetic resonance imaging and computed tomography effectively demonstrated the cricoarytenoid subluxation, which was confirmed by intraoperative electromyography (EMG) showing normal electrical activity in the thyroarytenoid muscle. Photographs from preoperative fiberoptic laryngoscopy are presented to identify the appearance of arytenoid subluxation. Computed tomographic findings and photographs from laryngoscopy of two patients with RLNP documented by intraoperative EMG evaluation are presented to help distinguish the clinical appearance of this disorder from arytenoid subluxation. An integrated approach to the diagnosis and treatment of arytenoid subluxation is presented.

Adult↗
PubMed1991

Evaluation, treatment, and follow-up results of post polio patients with dysphagia.

Twenty consecutive patients were evaluated for reports of dysphagia from post-polio clinics. Only half the patients reported a history of swallowing problems at the time of their acute poliomyelitis. Each patient received a videofluorographic evaluation of the oral and pharyngeal phases of swallowing, and then was provided with recommendations to improve swallowing skills. A follow-up questionnaire was sent to all patients. The respondents had an average interval of 12 months since the initial evaluation. Of the 18 patients responding to the questionnaire, 14 (77%) reported regular use of the swallowing suggestions. Comparison of pre-evaluation results to followup of the 18 respondents yielded a statistically significant decline in the frequency of choking (p = 0.0156) and food sticking in the throat (p = 0.0195). We conclude that a dysphagia program can result in significant improvement of the swallowing symptoms reported with the post-polio population.

Adult↗
PubMed1991

Mandibular reconstruction using vascularized bone grafts.

Total oromandibular reconstruction following cancer extirpation remains a significant challenge to the head and neck surgeon. Reconstructive goals must address occlusion, salivary continence, mastication, deglutition, and articulation. In this article, various methods of mandibular reconstruction, with special attention to the most recent advances in vascularized bone and free tissue transfer techniques, are reviewed.

Bone Transplantation↗
PubMed1991

Unilateral multicentric Warthin's tumors.

Papillary cystadenoma lymphomatosum, or Warthin's tumor, is known to have a high rate of multicentricity. An incidence of 5-14% is suggested by the literature. We present a female patient with three discrete masses noted in the superficial lobe of the parotid gland at the time of surgical resection. The epidemiology, histology and pathophysiology of Warthin's tumor is discussed and the need for adequate surgical resection is emphasized.

Adenolymphoma↗
PubMed1990

DNA analysis using polymerase chain reactions in the families of children with cystic fibrosis.

The results of our experience in DNA analysis in cystic fibrosis families using polymerase chain reaction (PCR) is reported. Of the first 10 families studied, seven were fully informative using the probe KM19 and PCR. In the remaining three families, Southern blotting analysis and the probe pXV2c were required before full information was obtained in two and partial information in the other family. The methods used, the current place of PCR and the clinical relevance of DNA analysis are discussed.

Blotting, Southern↗
PubMed1990

Amastatin potentiation of drinking induced by blood-borne angiotensin: evidence for mediation by endogenous brain angiotensin.

Angiotensinergic synapses in the central nervous system (CNS) have been proposed to be involved in drinking induced by both intracerebroventricular (i.c.v.) and peripheral administration of angiotensins. In the present studies, we tested this hypothesis with i.c.v. application of amastatin, an aminopeptidase A inhibitor, to block peptide degradation. Potentiation of i.c.v. angiotensin II (Ang II)-induced drinking responses was observed when amastatin and Ang II were administered. Amastatin did not potentiate drinking to carbachol which demonstrates that the enhancement is specific to peptides. Centrally administered amastatin also potentiated drinking following systemic administration of Asn1 angiotensin II. (Asn1 Ang II). The results are consistent with the hypothesis that CNS angiotensin synapses are involved in the dipsogenic response that results from elevated levels of circulating angiotensin.

Aminopeptidases↗
PubMed1990

Utility of emission tomography in evaluation of mandibular bone grafts.

Bone scanning, performed within 1 week postoperatively, is valuable in predicting the survival of revascularized composite flap grafts. Conventional planar scintigraphy is limited by a two-dimensional representation of three-dimensional structures. Single photon emission computed tomography (SPECT) is a technique in which a gamma camera rotates around the patient, acquires multiple projections, and with the aid of a computer, reconstructs three-dimensional representations. We wished to evaluate the potential advantages of SPECT in the assessment of mandibular graft viability and to compare it with planar scanning. These noninvasive methods of assessing the vascular supply are critical to patient management in the early postoperative period because the presence of or inability to exclude vascular compromise commands surgical exploration of the anastomosis for graft salvage. Fifteen patients who underwent mandibular reconstruction with revascularized free grafts were studied by both planar and SPECT scintigraphy. Long-term follow-up data were correlated with the outcome predicted by the scanning.

Adult↗
PubMed1990

The cutaneous scapular free flap in head and neck reconstruction.

Successful surgical reconstruction of complicated soft-tissue defects of the head and neck region has been greatly enhanced by free-revascularized tissue transfers. The scapular free flap has become a favored reconstructive option in our department and has been reported previously for one-stage mandibular reconstruction. This flap can also be transferred as a cutaneous free flap. We present our clinical experience with the fasciocutaneous scapular free flap and review the anatomy, surgical technique, and utility of this versatile flap.

Adult↗
PubMed1990

Recombinant gamma interferon in treatment of patients with atopic dermatitis and elevated IgE levels.

PURPOSE: Recombinant gamma interferon (rIFN-gamma) inhibits IgE synthesis in vitro by human peripheral blood mononuclear cells (PBMC). These data suggest a role for rIFN-gamma in the treatment of patients with severe atopic dermatitis (AD) and elevated IgE levels. The purpose of this study was to determine the effect of rIFN-gamma treatment on IgE production in patients with AD. PATIENTS AND METHODS: Twenty-two patients with chronic severe AD were treated with rIFN-gamma. In part I of the study, 14 patients were treated with daily subcutaneous injections at three successive dose levels (0.01 mg/m2, 0.05 mg/m2, and 0.1 mg/m2) for 5 days with 2 days off between each dose level. In part II, eight patients received rIFN-gamma at 0.05 mg/m2, daily for 6 weeks. One patient from part I and eight patients from part II of the study received three times per week maintenance thereby for up to 14 months. Prior to and at selected times during and after treatment, the clinical and immunologic status of the patients was assessed. RESULTS: In part I, spontaneous de novo IgE synthesis by PBMC was inhibited in 10 patients receiving rIFN-gamma at 0.01 mg/m2 (p = 0.038) and in nine at 0.1 mg/m2 (p = 0.066). There was no reduction of serum IgE levels at any of the three dose levels. Total clinical severity showed improvement at each dose level (p less than 0.04) with worsening 3 days after discontinuation of treatment. In part II, there was no significant inhibition of spontaneous IgE synthesis by PBMC nor was there any reduction of serum IgE. Nevertheless, there was a progressive and significant reduction (p less than 0.01) in total clinical severity over the 6 weeks of daily rIFN-gamma with a sustained improvement during maintenance therapy. CONCLUSION: The results of this pilot study suggest that rIFN-gamma may be efficacious in the treatment of AD and that further clinical trials are warranted.

Adolescent↗
PubMed1990

Immediate intraoperative tissue expansion.

We report a modification of the controlled tissue expansion technique, that is, immediate intraoperative tissue expansion. The procedure is performed by placing tissue expanders at the time of surgery. After placement, three to four cycles of inflation/deflation of the expander for 3 to 5 minutes are performed. In a one-stage procedure the stretched skin is then immediately used to close the surgical defect. Three case reports demonstrating the immediate intraoperative tissue expansion technique, in which the Foley catheter balloon was used as the tissue expander, are presented. These cases illustrate that this technique may allow the surgeon to cover defects more easily with less tension and with a better cosmetic result than with other closure techniques.

Adult↗
PubMed1990

Relation between catastrophizing and depression in chronic pain patients.

The relation between catastrophizing, depression, and pain was examined in 125 chronic pain patients. The Coping Strategies Questionnaire (CSQ; Rosenstiel & Keefe, 1983) assessed patients' use of cognitive and behavioral strategies to cope with chronic pain. A significant association between catastrophizing and depression was found. In order to address questions of measurement redundancy, 6 clinical psychologists rated the degree to which items on the CSQ reflected depressive symptomatology. All items contained in the Catastrophizing subscale were rated by all psychologists as being reflective of symptoms of depression and were removed from the CSQ. When this subscale was excluded, none of the remaining CSQ subscales were significantly related to depression. The discussion addresses the interpretive difficulties that arise from hypothesizing mediating relations between variables that are conceptually and operationally confounded.

Adaptation, Psychological↗
PubMed1990

Skeletal muscle biochemistry and histology in ambulatory patients with long-term heart failure.

Recent studies in patients with long-term heart failure have suggested that intrinsic abnormalities in skeletal muscle can contribute to the development of early lactic acidosis and fatigue during exercise. The present study provides an analysis of substrate and enzyme content, fiber typing, and capillarization in skeletal muscle biopsy samples obtained at rest from the vastus lateralis in 11 patients with long-term heart failure (left ventricular ejection fraction, 21 +/- 8%) and nine normal subjects. Patients demonstrated a reduced peak exercise oxygen consumption (13.0 +/- 3.3 ml/kg/min) when compared with normals (30.2 +/- 8.6 ml/kg/min, p less than 0.001) and had an accelerated rise in blood lactate levels during exercise. In mixed fiber skeletal muscle, total phosphorylase and glycolytic enzyme activities were not different in the two groups, whereas mitochondrial enzymes involved in terminal oxidation were decreased in patients as compared with normal subjects as indicated by reductions in succinate dehydrogenase (51 +/- 15 vs. 81 +/- 17 microM/g protein/min, p less than 0.001) and citrate synthetase (26 +/- 7 vs. 43 +/- 20 microM/g protein/min, p less than 0.05). 3-Hydroxyacyl-CoA-dehydrogenase, an important enzyme mediating beta-oxidation of fatty acids, was also reduced in patients as compared with normals (18 +/- 7 vs. 27 +/- 10 microM/g protein/min, p less than 0.05). There was no difference in high-energy phosphagens or lactate concentration of mixed muscle in the two groups, whereas glycogen content was decreased in patients (262 +/- 29 vs. 298 +/- 35 microM glucosyl units/kg dry wt, p = 0.01). Patients demonstrated a reduced percentage of slow twitch type I fibers (36 +/- 7% vs. 52 +/- 22%, p less than 0.05) and had a higher percentage of type IIb fast twitch fibers (24 +/- 9% vs. 11 +/- 12%, p = 0.02), which were smaller than the type IIb fibers seen in normal subjects (p less than 0.05). In patients, the number of capillaries per fiber was decreased for type I and type IIa fibers (both, p less than 0.03), but the ratio of capillaries to cross-sectional fiber area was not different for the two groups. These data demonstrate major alterations in skeletal muscle histology and biochemistry in patients with long-term heart failure, including fiber atrophy, a decrease in percentage of composition of type I fibers, and an increase in type IIb fibers accompanied by a decrease in oxidative enzyme capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Local control of auricular, periauricular, and external canal cutaneous malignancies with Mohs surgery.

Three hundred ninety-seven patients with 407 cutaneous malignancies of the auricle, periauricular region, and cartilaginous external ear canal were reviewed. Tumors were most commonly located in the preauricular and postauricular regions, followed by the helix, concha, antihelix, and ear canal. All lesions were excised with Mohs microscopic control of margins. For lesions requiring lateral temporal bone resection, an adaptation of fresh-tissue microscopic control was used to analyze deep and anterior margins suspected of harboring residual tumor. Two-year minimum follow-up of 229 patients with periauricular and auricular tumors (N = 231 tumors) and 14 patients with cartilaginous ear canal tumors (N = 14 tumors) revealed recurrence rates of 6.9% and 14.3%, respectively. Recurrences were most common in cases of large tumors (greater than 2.5 cm), basal cell carcinomas with morphea elements, and multiply recurrent lesions. We conclude that Mohs surgery is comparatively effective, though not uniformly curative, and can be adapted to supplement excision of large tumors in these regions.

Basal Cell Carcinoma↗