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Biomedical subjects

T Little

Publications and source records attributed to T Little.

At least 19 recordsLinked to original sources
PubMed2000

Angiotensin-converting enzyme genotype affects the response of human skeletal muscle to functional overload.

The response to strength training varies widely between individuals and is considerably influenced by genetic variables, which until now, have remained unidentified. The deletion (D), rather than the insertion (I), variant of the human angiotensin-converting enzyme (ACE) genotype is an important factor in the hypertrophic response of cardiac muscle to exercise and could also be involved in skeletal muscle hypertrophy - an important factor in the response to functional overload. Subjects were 33 healthy male volunteers with no experience of strength training. We examined the effect of ACE genotype upon changes in strength of quadriceps muscles in response to 9 weeks of specific strength training (isometric or dynamic). There was a significant interaction between ACE genotype and isometric training with greater strength gains shown by subjects with the D allele (mean +/- S.E.M.: II, 9.0+/-1.7 %; ID, 17.6 +/-2.2 %; DD, 14.9+/-1.3 %, ANOVA, P 0.05). A consistent genotype and training interaction (ID DD II) was observed across all of the strength measures, and both types of training. ACE genotype is the first genetic factor to be identified in the response of skeletal muscle to strength training. The association of the ACE I/D polymorphism with the responses of cardiac and skeletal muscle to functional overload indicates that they may share a common mechanism. These findings suggest a novel mechanism, involving the renin-angiotensin system, in the response of skeletal muscle to functional overload and may have implications for the management of conditions such as muscle wasting disorders, prolonged bed rest, ageing and rehabilitation, where muscle weakness may limit function.

Adolescent↗
PubMed1999

Vasoseal hemostasis following coronary interventions with abciximab.

Femoral arteriotomy management using a collagen vascular hemostasis device (VasoSeal, Datascope Corporation, Montvale, New Jersey) was studied in 50 consecutive patients following interventional coronary procedures performed with abciximab (ReoPro, Eli Lilly and Company, Indianapolis, Indiana). Low-dose weight-adjusted or no heparin was employed. The first 25 patients were permitted to sit up after 6 hours with ambulation the following day. The second 25 patients were allowed to sit up after 1 hour and ambulate after 6 hours. Despite early activity and ambulation, there were no hemorrhagic complications including hematoma, pseudoaneurysm, blood transfusion, or surgical repair. Hemoglobin and platelet counts remained stable overnight prior to discharge. This pilot study demonstrates the potential efficacy of VasoSeal in achieving early sheath removal and ambulation in patients undergoing interventional procedures using ReoPro.

Abciximab↗
PubMed1998

Highly efficient and versatile synthesis of libraries of constrained beta-strand mimetics.

The general approach of using a bicyclic template to produce inhibitors of the protease superfamily of enzymes has been investigated. The Diels Alder cycloaddition reaction on solid support has been found to be highly efficient for the synthesis of libraries of compounds that mimic the beta-strand secondary structure of proteins. Several potent and selective inhibitors of proteases have been discovered.

Bridged Bicyclo Compounds, Heterocyclic↗
PubMed1998

Vasoseal hemostasis following coronary interventions with Abciximab.

Femoral arteriotomy management using a collagen vascular hemostasis device (VasoSeal) was studied in 50 consecutive patients following interventional coronary procedures performed with Abciximab (ReoPro). Low dose weight adjusted or no heparin was employed. The first 25 patients were permitted to sit up after 6 hours with ambulation the following day. The second 25 patients were allowed to sit up after 1 hour and ambulate after 6 hours. Despite early activity and ambulation, there were no hemorrhagic complications including hematoma, pseudoaneurysm, blood transfusion, or surgical repair. Hemoglobin and platelet counts remained stable overnight prior to discharge. This pilot study demonstrates the potential efficacy of VasoSeal in achieving early sheath removal and ambulation in patients undergoing interventional procedures using ReoPro.

Abciximab↗
PubMed1996

Immediate and long-term results of the splinting for acute closure trial.

The ability of coronary splinting to salvage acute coronary occlusion was prospectively studied in 22 patients whose coronary occlusion was refractory to a 15-min balloon dilatation. Splinting was successful in 20 patients (91%). One patient required emergency bypass surgery, and one patient was treated medically for continued coronary occlusion. There was no late ischemic events. The peak CK was 1081 +/- 733 U/L and 1,451 +/- 1,646 U/L for the study and control patients (P = NS). The peak CK-MB was 110 +/- 102 mg/dl and 78 +/- 84 mg/dl, respectively (P = NS). There were no differences in electrocardiographic changes or Q-wave myocardial infarction between the groups. At 6-month follow-up, one patient required coronary artery bypass graft surgery. There were no late myocardial infarctions or deaths.

Aged↗
PubMed1996

Cardiopulmonary changes with moderate decompression in rats.

Sprague-Dawley rats were compressed to 616 kPa (a) for 120 min then decompressed at 38 kPa/min to assess the cardiovascular and pulmonary responses to moderate decompression stress. In one series of experiments the rats were chronically instrumented with Doppler ultrasonic probes for simultaneous measurement of blood pressure, cardiac output, heart rate, left and right ventricular wall thickening fraction, and venous bubble detection. Data were collected at baseline, throughout the compression/decompression protocol, and for 120 min post decompression. In a second series of experiments the pulmonary responses to the decompression protocol were evaluated in non-instrumented rats. Analyses included blood gases, pleural and bronchoalveolar lavage (BAL) protein and hemoglobin concentration, pulmonary edema, BAL and lung tissue phospholipids, lung compliance, and cell counts. Venous bubbles were directly observed in 90% of the rats where immediate post-decompression autopsy was performed and in 37% using implanted Doppler monitors. Cardiac output, stroke volume, and right ventricular wall thickening fractions were significantly decreased post decompression, whereas systemic vascular resistance was increased suggesting a decrease in venous return. BAL Hb and total protein levels were increased 0 and 60 min post decompression; pleural and plasma levels were unchanged. BAL white blood cells and neutrophil percentages were increased 0 and 60 min post decompression and pulmonary edema was detected. Venous bubbles produced with moderate decompression profiles give detectable cardiovascular and pulmonary responses in the rat.

Animals↗
PubMed1995

Combined use of the esophageal-tracheal Combitube with a colorimetric carbon dioxide detector for emergency intubation/ventilation.

OBJECTIVE: The esophageal-tracheal Combitube (Sheridan, Inc., Argyle, NY) is a unique double lumen tube that has been introduced as an emergency intubation device. Since it is placed blindly, proper use requires determination of which lumen can be successfully used for ventilation. The Easycap (Nellcor, Inc., Pleasanton, CA) is a colorimetric carbon dioxide detector that reacts with exhaled gas to indicate proper tracheal tube location. The purpose of this study was to determine if the Easycap can be used to identify which Combitube lumen is patent to the trachea after blind placement in dogs. METHODS AND RESULTS: The study was conducted using 8 anesthetized dogs. In each of 15 blind insertions of the Combitube, the Easycap device responded appropriately by changing color from purple to yellow when connected to the lumen communicating with the trachea. When the Easycap device was connected to the alternate lumen, no color change was appropriately observed in 9 out of 15 cases (60%) after 6 breaths; in 4 of the remaining 6 (87%, total), no color change was noted after 12 breaths. In the 2 remaining cases, the color change indicated the need of further verification of the tube location. In separate experiments, 10 direct tracheal and esophageal insertions of the Combitube were correctly verified by the appropriate Easycap color change. CONCLUSIONS: Our results suggest that the Easycap device may be useful with the Combitube, although human data are required.

Animals↗
PubMed1994

Morbidity and mortality rates in elderly patients undergoing percutaneous coronary transluminal angioplasty.

Although successful dilatation of a target lesion by means of percutaneous transluminal coronary angioplasty (PTCA) can be attained as frequently in elderly as in younger patients, elderly patients have a higher risk of complications. Furthermore, cohorts of patients older than 75 years and undergoing PTCA include more women and more cases of unstable angina, factors that increase the risk of complications. Included in this analysis of 3199 PTCAs performed between January 1991 and September 1992 were 474 (14.8%) patients who were > or = 75 years old. Age was an independent risk factor for death, acute myocardial infarction, need for transfusion, and need for arterial repair after PTCA. The frequency of successful dilatation of individual lesions, emergency coronary bypass surgery, or repeated PTCA of the same lesion was not related to age. In previous studies no association has been demonstrated between age and increased risk of in-hospital reclosure. The presence of more severe coronary disease and of the greater frequency of coexisting morbid conditions makes elderly patients less able to tolerate unsuccessful or complicated PTCA.

Age Factors↗
PubMed1994

Developmental patterns of expected consequences for simulated bicycle injury events.

Bicycle injuries follow a developmental pattern that differs from that of most injuries, where toddlers and individuals in young adulthood are most at risk. Children in late childhood and early adolescence appear most at risk for bicycle injuries. The present study of 2nd-grade, 4th-grade, 6th-grade, and undergraduate college students documented that after videotaped simulations of bicycle injury events, younger children anticipated greater injury severity and more fear than older children and adolescents. The potential influence of reduced expectations for injury with increasing age is described, and challenges are advanced for establishing the link between lowered injury expectancies and increased risky behavior.

Adolescent↗
PubMed1993

Late outcome and quality of life following percutaneous transluminal coronary angioplasty in octogenarians.

Limited data are available concerning the long-term survival and quality of life of octogenarians treated with percutaneous transluminal coronary angioplasty (PTCA). We retrospectively compared the results of PTCA in 118 octogenarians to that of 500 younger subjects. Among the octogenarians, long term follow-up was obtained including survival, relief of angina, assessment of quality of life, and capacity for independent living. These results were compared between men and women. The clinical success rate was 93% for the octogenarians and 88% for the younger patients (p = NS). The lesion success rates were 89% and 88% for these groups, respectively. Results of multilesion PTCA and dilatation of coronary occlusions were similar in both age groups. Major complication rates were 5.9% for the elderly and 3.8% for the younger patients (p < .008). Hospital mortality was higher among the octogenarians (4.6% vs 0.2%, p < .05). Among long-term octogenarian survivors, > 90% indicated a high level of satisfaction with their quality of life and health status. If needed, 88% would undergo the procedure again. Independent living was possible for 66% of these patients and automobile driving for 55%. Octogenarian men and women had similar baseline clinical characteristics, procedural success, complications, relief of angina, and survival. Women indicated a slightly lower level of satisfaction and capacity for independent living. PTCA can achieve a success rate in octogenarians comparable to that of younger patients but with an increased risk of serious complications. Patient satisfaction remains high and a majority of octogenarians remain physically active and capable of independent living.

Activities of Daily Living↗
PubMed1993

Catheter lavage and drainage of pneumococcal pericarditis.

An 88 year old woman with streptococcal pneumonia developed purulent pericarditis and cardiac tamponade despite treatment with antibiotics. Percutaneous pericardial drainage was effected with a 6 French pigtail catheter inserted via the subxyphoid approach. Catheter drainage was continued for 7 days in conjunction with systemic antibiotics. Catheter patency was maintained with antibiotic lavage. Immediate hemodynamic improvement followed the initial pericardial drainage. Fever, leukocytosis, and sepsis resolved during the course of therapy. The patient recovered fully from the closed space bacterial infection without additional surgical drainage. There has been no recurrence of streptococcal infection and no echocardiographic evidence of recurrent pericardial effusion after 3 months of follow-up. Indwelling catheter drainage combined with antibiotics may be an effective substitute for surgical drainage in the treatment of streptococcal pericarditis.

Aged↗
PubMed1992

Prolonged coronary splinting in the management of acute coronary closure.

Acute closure is an infrequent but serious complication of PTCA that is often unsuccessfully treated by repeat dilatation. Two patients with acute closure refractory to repeat conventional PTCA were treated with prolonged coronary "splinting" using low-pressure reperfusion catheter balloon inflations of 11 and 15 h duration. The patients developed no chest pain or ST-segment changes during this period. The serum creatine kinase rose to 738 and 372 U/L, respectively. Neither patient evolved a Q-wave myocardial infarction. Both patients remain asymptomatic after 6 months of follow-up.

Aged↗
PubMed1992

Narcissism and object relations.

Questionnaire measures of the narcissistic personality disorder can predict healthy and unhealthy self-functioning. That this outcome might support Heinz Kohut's psychoanalytic psychology of the self was tested in a sample of 354 undergraduates. In canonical correlations, factors from the Narcissistic Personality Inventory were associated more strongly with grandiose than with idealizing immaturities in Kohut's bipolar self, while difficulties in interpersonal relationships (i.e., poor object relations) were associated more strongly with idealizing deficits. Zero-order and partial correlational data were congruent with Kohut's hypothesis that self-grandiosity can include elements of both "pathology" and relative mental health, but canonical correlations did not support Kohut's claim that narcissism can be described in a bidimensional self-structure.

Adolescent↗
PubMed1991

Effects of time required for reperfusion (thrombolysis or angioplasty, or both) and location of acute myocardial infarction on left ventricular functional reserve capacity several months later.

The purpose of this study was to determine whether reperfusion of acute myocardial infarction (AMI) by recombinant tissue-type plasminogen activator (rt-PA) or percutaneous transluminal coronary angioplasty, or both, would improve left ventricular (LV) function when it is measured several months later at rest or maximal bicycle exercise, or both. Radionuclide angiography was performed in 44 patients 5 months (range 6 weeks to 9 months) after AMI to assess function, and tomographic myocardial thallium-201 imaging was performed at maximal exercise and delayed rest to determine whether there was any evidence of myocardial ischemia. As expected, no patient had chest pain or redistribution of a thallium defect during the exercise test, because patients had undergone angioplasty (n = 28) or coronary bypass graft surgery (n = 5) where clinically indicated for revascularization. The LV ejection fraction was plotted as a function of the time elapsed between the onset of chest pain and the time when coronary angiography confirmed patency of the infarct-related artery (achieved in 91% of 44 patients by rt-PA [n = 31] or percutaneous transluminal coronary angioplasty [n = 9] ). Functional responses differed markedly between patients with anterior (n = 20) versus inferior (n = 24) wall AMI. LV ejection fraction during exercise correlated with time to reperfusion in patients with an anterior wall AMI (r = -0.58; standard error of the estimate = 11.9%; p less than 0.02) but not in patients with an inferior AMI (r = 0.10; standard error of the estimate = 13.1%; difference not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1991

A comparison of multilesion percutaneous transluminal coronary angioplasty in elderly patients (greater than 70 years) and younger subjects.

Results of multilesion percutaneous transluminal coronary angioplasty (PTCA) were compared in 210 elderly patients (70 to 92 years, [group I] and 210 younger patients (40 to 69 years, [group II]. The elderly patients included more women (43% versus 24%) and patients with unstable angina (73% versus 55%). PTCA was successful in 87% of lesions in group I and in 94% in group II (p less than 0.001). Only circumflex artery dilatation was less successful in group I (78% versus 91%, p less than 0.002). PTCA was successful in all lesions of at least one vessel in 89% of group I patients and in 94% of group II patients (p less than 0.06). Successful dilatation of all lesions was achieved in 77% of group I and in 85% of group II patients (p less than 0.05). Complication rates were similar for both groups. These data demonstrate a high rate of success and safety in elderly patients undergoing multilesion PTCA despite the presence of several risk factors (advanced age, female sex, unstable angina). The lower PTCA success rate in these patients compared with younger subjects is almost entirely attributable to reduced success for circumflex artery lesions.

Age Factors↗
PubMed1990

Probe angioplasty of total coronary occlusion using the Probing Catheter technique.

Coronary angioplasty (PTCA) of total coronary occlusion is limited by the inability of guidewires and conventional dilating catheters to cross all such lesions. A new technique was therefore prospectively evaluated for PTCA of these lesions using the ultra-low-profile Probe "balloon on a wire" device. An intracoronary Probing Catheter was used to facilitate crossing the stenosis with a guidewire and then to deliver a Probe into the obstruction for balloon dilatation. This technique was utilized in 64 consecutive patients with "absolute" coronary occlusions demonstrating no angiographically detectable antegrade coronary flow. Successful dilatation was achieved in 47 (73%). Among 33 occlusions of less than 3 mo duration 31 (94%) were successfully dilated whereas only 16 of 31 more chronic occlusions were dilated (P less than .01). Chronic occlusions with a tapered morphology and those located more than 1 cm from a branch point were more frequently dilatable. There were no serious complications including no vessel perforations with this technique. The Probing Catheter technique offers a safe and effective method for the dilatation of recent coronary occlusions by using balloon on a wire technology.

Angioplasty, Balloon, Coronary↗