Search PubMed⌕ Search

Biomedical subjects

S J Sullivan

Publications and source records attributed to S J Sullivan.

At least 37 records · Page 2Linked to original sources
PubMed1995

Rapid assay for mycobacterial growth and antibiotic susceptibility using gel microdrop encapsulation.

Effective control of tuberculosis transmission in vulnerable population groups is dependent on rapid identification of the infectious agent and its drug susceptibility. However, the slow growth rate of mycobacteria has undermined the ability to quickly identify antimicrobial resistance. These studies describe a mycobacterial growth assay based on microencapsulation technology used in conjunction with flow cytometric analysis. Mycobacteria were encapsulated in agarose gel microdrops approximately 25 microns in diameter, and colony growth was monitored by using flow cytometry to evaluate the intensity of auramine staining after culture for various times at 37 degrees C. By this method, colony growth of Mycobacterium bovis and M. smegmatis could be quantified within 1 to 3 days after encapsulation. Inhibition of growth by rifampin and isoniazid was also evaluated in this time period, and the presence of an isoniazid-resistant subpopulation representing 3% of the total microorganisms could be detected. This use of encapsulation and flow cytometry has the potential to facilitate rapid and automated evaluation of inhibition of growth by antimicrobial agents and shorten the time frame for analysis of clinical specimens.

Bacteriological Techniques↗
PubMed1995

Changes in the hemiparetic limb with training. I. Torque output.

The study concerns eleven patients who had suffered from a cerebro-vascular accident (CVA) less than 6 months previously and who were hospitalized for treatment. In addition to their multidisciplinary rehabilitation treatments, the patients consented to participate in an electromyographic (EMG) biofeedback program designed to increase their shoulder activity. From blocks of five individual isometric contractions, curves of both the mean torque and of its standard deviation (SD) were generated and from each of these, a mean value was obtained. These two measures were used to analyze the effects on the biofeedback training had induced on shoulder activity. The training induced negligible changes on the contralateral (CL) side. The mean torque value for the group was 31.02 post vs 30.99 Nm pre-training. However, for the hemiplegic (HEMI) limbs, some patients showed improvement while others did not. The treatment was considered a success when the mean torque values obtained in the last 2/3 of the training or at the post-training session were > or = 1.5 the values obtained during the pre-training session. Based on this criteria, it was found that six out of eleven patients did improve their muscular activity through the training. Among these, the improvement of four was greater during the 2/3 session than that observed at the post-training session. The six successful patients were found to have a pre-training upper extremity Fugl-Meyer score < or = 13. Two patients had a similar pre-training score of 11, and met the criteria of success, but the younger patient performed better than the older one. Patients with scores of 20 and higher did not meet the 1.5 criteria. A correlation (r = 0.80) was found between post/pre ratios of Fugl-Meyer scores and those of the mean torque: the test thus seems to have a limited usefulness for assessing local changes such as the effects of the biofeedback treatment on the shoulder.

Adult↗
PubMed1994

The effect of therapeutic massage on H-reflex amplitude in persons with a spinal cord injury.

BACKGROUND AND PURPOSE: The effect of therapeutic massage on the H-reflex amplitude in persons without neurological impairment has been established. To investigate its effects in a sample of persons with a spinal cord injury (SCI), two independent but interrelated studies were undertaken. Study 1 investigated whether the recorded response (H-reflex amplitude) to massage with the subjects in the supine testing position was similar to that recorded in previous studies in which the subjects were tested in the prone position. This study was undertaken because the prone testing position was considered inappropriate for persons with SCI. In study 2, the therapeutic effect of massage (petrissage) on H-reflex amplitude in persons with SCI was examined. SUBJECTS: Seven persons without neurological impairment volunteered to participate in study 1, and 10 individuals with a traumatic SCI volunteered to participate in study 2. METHODS: The two studies shared many methodological features and involved the recording of 10 H-reflex and M-response peak-to-peak amplitudes from the triceps surae muscle during each of five sequential, 3-minute time periods. Massage treatment (MASS) was given during the third time period, and the premassage time periods (C1, C2) and postmassage time periods (C3, C4) served as control conditions. Study 2, in addition to recording the peak-to-peak amplitudes of the recorded responses, also included the recording of the H-reflex latencies. RESULTS: The results of study 1 showed that massage applied with the subjects in the supine position decreased the H-reflex amplitude during the massage. A 56% decrease in the H-reflex amplitude was recorded. Study 2 demonstrated a 27% mean group decrease in the H-reflex peak-to-peak amplitude during the massage for all subjects, with variations in individual responses ranging from an increase in the H-reflex amplitude of 20% to a decrease of 84%. An analysis of variance revealed that the H-reflex means of the five conditions were significantly different. Newman-Keuls post hoc analyses revealed that the mean of the MASS condition (2.01 mV) was significantly different from the means of C1, C2, and C4 (2.79, 2.81, 2.58 mV). The mean of C3 (2.42 mV) was not found to be statistically different from the means of the other conditions. These changes were noted against a stable M-response. CONCLUSION AND DISCUSSION: The results recorded in study 1 are comparable to those obtained with the subjects in the prone position. Based on these results, the supine position was adopted as the testing position for study 2. Study 2 further showed a decrease in H-reflex amplitude concomitant with massage in persons with SCI, but no long-term effects were noted.

Adult↗
PubMed1994

Agreement of classification decisions using two measures of motor co-ordination in persons with a traumatic brain injury.

Identification of motor co-ordination deficits in persons with a traumatic brain injury (TBI) is a vital part of both assessment and rehabilitation. The purpose of this study was to investigate the agreement of classification decisions based on clinical (subjective) and instrumented (objective) tests for measuring upper-limb co-ordination in persons with a TBI. Twenty-two subjects with TBI performed the 'finger-to-nose' test and a 'lateral reach tapping test' 12 months post-injury. After reduction to categorical form (deficit/no deficit), the data were interpreted using a generalized kappa statistic, to estimate the agreement between the two tests. The kappa values for the right and left upper extremities were 0.625 and 0.360, respectively, while the combined (right and left) value was 0.500, representing only 'moderate' agreement between the two testing protocols. This indicates that motor co-ordination deficits in persons with TBI can be documented using either clinical or instrumented tests. The choice of test does not appear to be based on the subjective/objective nature (dimension) of each test, but rather on more practical factors such as administration time, cost and level of objectivity desired by the clinician.

Adolescent↗
PubMed1993

Reliability of the scores for the finger-to-nose test in adults with traumatic brain injury.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the intrarater and interrater reliability of measurements of three clinical features of coordination based on the performance of the "finger-to-nose" test. SUBJECTS: Thirty-seven persons with traumatic brain injury (26 male, 11 female), aged 17 to 64 years (mean = 29.1, SD = 9.9), participated in the study. METHODS: Each subject's performance was videotaped and evaluated for the right and left upper extremities (UEs) (two trials each) with respect to the following variables: time of execution, degree of dysmetria, and degree of tremor (four-point ordinal ratings). One year later, five experienced physical therapists (including the original investigator) independently rated each patient's videotaped performance in the same manner as described above. RESULTS: Intraclass correlation coefficients (ICC[3,1]) for intrarater reliability were .971 and .986 and ICCs for interrater reliability were .920 and .913 for right and left UEs, respectively, for the time of execution. A generalized Kappa statistic of .54 was calculated for the scoring of dysmetria (both UEs), and Kappa statistics calculated for the scoring of tremor were .18 and .31 for right and left UEs, respectively. Interrater reliability was lower for the scoring of these variables and varied from .36 to .40 for dysmetria and from .27 to .26 for tremor (right and left UEs, respectively). CONCLUSION AND DISCUSSION: These results indicate that physical therapists demonstrate low reliability in assessment of the presence of dysmetria and tremor using videotaped performances of the finger-to-nose test. The results suggest, however, that therapists reliably measure the time of execution of this test. If the limitations associated with therapists' capacity for objective measurement of subjective phenomena cannot be overcome (eg, by establishment of more definitive scoring criteria for the measures of dysmetria and tremor), then therapists should seek alternative methods of evaluation of UE coordination.

Adolescent↗
PubMed1993

Treatment of severe diabetes mellitus for more than one year using a vascularized hybrid artificial pancreas.

We report the successful application of a hybrid artificial pancreas device for the treatment of severe diabetes mellitus induced by total pancreatectomy in two dogs. Control of the blood sugar was achieved for more than 1 year in these two animals without any immunosuppressive therapy. Although exogenous insulin was required therapy. Although exogenous insulin was required during the latter part of the study period, removal of the devices resulted in a rapid increase in the fasting blood sugar levels and the exogenous insulin requirements (P < 0.001 versus weeks 1-52 in both dogs). Metabolic studies, postexplant in vitro studies, and histologic analyses confirmed islet cell survival and insulin production by the devices. This hybrid artificial pancreas has a clear clinical potential for islet cell transplantation without immunosuppression.

Animals↗
PubMed1992

Allotransplantation of canine pancreatic islets.

The complications of diabetes continue to present significant health risks despite improvements in conventional insulin therapy. Transplantation of pancreatic islet tissue has the potential to provide more precise glucose regulation and possibly minimize these implications. Recent advances in pancreatic islet isolation technology have facilitated investigation of islet allograft function in large animal models. These studies are fundamental to the development of methods for transplantation of allogeneic or xenogeneic islets in diabetic patients. This paper reviews the approaches which have been taken to prevent rejection and allow assessment of islet allograft function in the pancreatectomized dog model. These approaches include immunosuppression, immunomodulation of the donor tissue and isolation of allogeneic tissue within an immunoprotective membrane.

Animals↗
PubMed1992

The effect of two intensities of massage on H-reflex amplitude.

The purposes of this study were (1) to investigate the effectiveness of two different levels of massage on the depression of spinal motoneuron excitability (as demonstrated by peak-to-peak H-reflex amplitude changes), (2) to investigate the presence of any gender effects in relation to massage, and (3) to describe a method used to quantify the amount of pressure exerted during two different intensities of massage. Two levels of massage were quantified and defined as light massage (LM) and deep massage (DM). These levels of massage corresponded to pressures of 1.25 and 2.50 kPa (5 and 10 in H2O), respectively. The therapist, before beginning the investigation, was trained to deliver these pressures. Ten peak-to-peak H-reflex recordings were elicited from the triceps surae muscle of each of 20 neurologically healthy subjects (10 male, 10 female) (mean age = 22.6 years) during five control and the two massage conditions. Each condition was 3 minutes in duration. Significant differences were found among the resulting means. The peak-to-peak H-reflex amplitudes recorded during the DM condition were reduced in comparison with those recorded during the LM condition. The peak-to-peak H-reflex amplitudes during both massage conditions were reduced in comparison with those recorded during the control conditions. These changes were noted against a stable M-response. This suggests that the mechanism involved in the observed inhibitory response is pressure sensitive, with DM bringing about a greater inhibitory response than did LM. No differential effects attributable to gender differences were found. These results will serve to define massage characteristics in an ongoing study investigating the effect of massage in persons with a spinal cord injury.

Adult↗
PubMed1992

A stable O2-resistant cell line: role of lipid peroxidation byproducts in O2-mediated injury.

HA-1 hamster fibroblasts receiving fresh media every 24 h were continuously passaged in progressively increasing O2 concentrations for 18 mo (designated O2R95). These cells were significantly more resistant than parental HA-1 to clonogenic inactivation mediated by 95% O2 without media replacement. The O2R95 cell line exhibited increases in the activities of catalase (CAT), Mn superoxide dismutase (MnSOD), Cu,Zn superoxide dismutase (Cu,Zn SOD), and glutathione peroxidase (GPx). O2R95 cells demonstrated uniformly distributed increased staining for CAT, MnSOD, Cu,Zn SOD, and GPx proteins, as determined by immunohistochemistry. Cellular resistance to and metabolism of 4-hydroxy-2-nonenal (4HNE), a toxic byproduct of lipid peroxidation implicated in mechanisms of O2 toxicity, was examined in HA-1 and O2R95 cell lines. O2R95 cells were significantly more resistant to 4HNE cytotoxicity, which was accompanied by a significant increase in 4HNE metabolism. O2R95 cells also demonstrated an increase in total glutathione (GSH) and glutathione S-transferase (GST) activity, an enzymatic system believed to be involved with 4HNE metabolism. Furthermore, homogenates from O2R95 cells consumed greater quantities of 4HNE in the presence of NADPH (but not NADH, NAD+, or NADP+), suggesting that an enzyme(s) utilizing NADPH contributes to 4HNE metabolism, resistance to 95% O2 and 4HNE as well as increased total GSH, antioxidant enzyme activities, and NADPH-dependent metabolism of 4HNE, persisted in O2R95 cells for 75 days of growth in 21% O2. These findings are compatible with the hypothesis that aldehydic byproducts of lipid peroxidation contribute to mechanisms of O2 toxicity and the selective pressure exerted by exposure of cells to hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Perspectives in diabetes. Islet transplantation with immunoisolation.

Immunoisolation is a potentially important approach to transplanting islets without need for immunosuppressive drugs. Immunoisolation systems have been conceived in which the transplanted tissue is separated from the immune system of the host by an artificial barrier. These systems offer a solution to the problem of human islet procurement by permitting use of islets isolated from animal pancreases. The devices used are referred to as biohybrid artificial organs because they combine synthetic, selectively permeable membranes that block immune rejection with living transplants. Three major types of biohybrid pancreas devices have been studied. These include devices anastomosed to the vascular system as AV shunts, diffusion chambers, and microcapsules. Results in diabetic rodents and dogs indicate that biohybrid pancreas devices significantly improve glucose homeostasis and can function for more than a year. Recent progress made with this approach is discussed, and some of the remaining problems that must be resolved to bring this technology to clinical reality are addressed.

Animals↗
PubMed1992

Treatment of severely diabetic pancreatectomized dogs using a diffusion-based hybrid pancreas.

Long-term survival of dog islet allografts implanted in diabetic pancreatectomized dogs was achieved by islet encapsulation inside cylindrical chambers fabricated from permselective acrylic membranes (nominal M(r) exclusion of 50,000-80,000). Dog islets were isolated from the pancreases of outbred mongrel dogs by collagenase digestion. Chambers containing mean +/- SE 316 +/- 63K islet equivalents (mean islet volume, 558 +/- 111 mm3, purity 90-95%) were peritoneally implanted into six totally pancreatectomized dogs. The dogs were monitored for glycemic control by fasting and postprandial blood glucose determinations, and responses to both intravenous glucose (intravenous glucose tolerance test 0.5 g/kg) and oral glucose (oral glucose tolerance test 1 g/kg). All of the dogs required appreciably lower dosages of exogenous insulin therapy for control of fasting blood glucose levels, with the mean daily insulin dose dropping from 38 +/- 7 to 5 +/- 1 U/day during the 1st wk. Three recipients required no insulin for greater than 82, greater than 68, and 51 days. Intravenous glucose tolerance test K values (decline in glucose levels, %/min) at 1 and 2 mo postimplantation were 2.7 +/- 0.4 and 2.0 +/- 0.5, respectively compared with 3.5 +/- 0.5 before pancreatectomy. The glucose values during oral glucose tolerance tests at 2 wk, although returning to less than 125 mg/dl (less than 7.0 mM) by 2 h, exceeded the normal range, with peak values of 174 to 202 mg/dl (9.7 to 11.3 mM). These preliminary results are encouraging, and represent an important step in determining the feasibility of using this type of diffusion-based hybrid artificial pancreas as treatment for diabetes mellitus in humans.

Animals↗
PubMed1992

Relation between clinical and instrumented measures of motor coordination in traumatically brain injured persons.

Right and left upper extremity motor coordination was evaluated in 40 traumatically brain injured subjects using two different measurement techniques--a conventional clinical evaluation and an instrumented evaluation. The relationship between the results from the clinical evaluation (finger to nose test) and the instrumented evaluation (timed visual-arm coordinated lateral reach) was determined using canonical correlation analysis (Rc). Clinical and instrumented test scores were significantly correlated (Rc = .685, p = .002; Rc = .629, p = .008 for the right and left sides, respectively). The scores obtained by the clinical test had little variance; instrumented scores varied greatly among subjects. Significant differences did not exist between the right and left sides for the instrumented variables of average movement speed, accuracy, and index of coordination (paired t-tests, p = .550, p = .548, p = .627, respectively) or for the clinical variables of time of execution (paired t-test, p = .468) and tremor (Wilcoxon matched-pairs, p = .228). Although meaningful correlations were obtained, they do not conclusively indicate that the two tests measure the same concept of coordination. Therefore, it is suggested that the instrumented evaluation be used to complement the traditional clinical evaluation to increase the degree of objectivity in clinical measurement.

Adolescent↗