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Biomedical subjects

J D Fisher

Publications and source records attributed to J D Fisher.

At least 19 recordsLinked to original sources
PubMed2005

An empirical test of the information, motivation and behavioral skills model of antiretroviral therapy adherence.

Nearly perfect adherence to demanding antiretroviral therapy (ART) is now recognized as essential for HIV-positive patients to realize its life sustaining benefits. Despite the dire consequences of non-adherence, a large number of patients do not follow their ART regimen. While many factors influence adherence, the literature is dominated by studies on only one or a small set of them. Multivariate, theory-based models of adherence behavior are of great interest. The current study tested one such model, the Information, Motivation and Behavioral Skills (IMB) model of ART adherence (Fisher et al., under review). A sample of HIV-positive patients on ART in clinical care in Puerto Rico (N=200) provided data on adherence-related information, motivation and behavioral skills as well as adherence behavior per se. Structural equation model tests used to assess the propositions of the IMB model of ART adherence provided support for the interrelations between the elements proposed by the model and extended previous work. Implications for future research and intervention development are discussed.

Adult↗
PubMed2001

Determinants of HIV risk among Indian truck drivers.

Although there are very high levels of HIV risk sexual behavior in India, there has been little research on the determinants of this behavior, the psychosocial correlates of condom use, or the potential for effective behavior change interventions. The present research used the information-motivation-behavioral skills model of HIV risk behavior to explore these issues in a sample of Indian truck drivers, a population that comprises an important vector of HIV transmission. This paper presents correlational data on the predictors of HIV risk and preventive behavior in a sample of truck drivers in Chennai, India. The data were collected via detailed individual structured interviews with 300 Indian truck drivers. Results indicated that Indian truck drivers had substantial deficits with respect to HIV prevention information, motivation, and behavioral skills. Consistent with the IMB model, these deficits were often found to be predictive of HIV risk and preventive behavior. The implications of these findings for future intervention are discussed.

Adult↗
PubMed2001

Linear lesion radiofrequency ablation in canine vagal atrial fibrillation: effects of special catheters designed for efficiency, and the critical role of lesions from the crista terminalis to the superior vena cava.

OBJECTIVE: To determine whether specially devised catheters could be used to place radiofrequency (RF) linear lesions quickly and efficiently for termination and/or prevention of atrial fibrillation (AF). METHODS: Two versions of 2 different types of ablating catheters were used in 12 canines with AF induced by rapid pacing during vagal stimulation. 1) Modified basket catheters in two versions, one designed to produce caudo-cranial linear lesions through extended bare electrode-splines in contact with the atrial wall; and the other designed to produce horizontal linear lesions by revolving within the atrium. Together these would form "longitude and latitude" grids in the atrium. 2) The second catheter type was 2 versions of coil electrodes with thermocouples centered under each of the large-area coil electrodes. One version of these deflectable coil electrodes was intended to produce lesions in the tricuspid valve annulus-inferior vena cava (IVC) isthmus; and along the crista terminalis from the superior vena cava (SVC) to the IVC. A different type of deflection angulation on the second version was intended to produce more horizontal lesions from the crista to the tricuspid annulus. Guidance was fluoroscopic, and by electrograms and transesophageal echo. Gross pathologic examinations followed each experiment. Prior to use in canines, all electrode configurations were tested in vitro on fresh bovine preparations suspended in saline at 37 degrees C. RESULTS: The bare spline and coil electrode catheter configurations produced discrete non-perforating non-charring lesions in the in vitro preparations. One dog died of exsanginating hemorrhage. Post mortem examination revealed the lesions to be extremely variable, ranging from no evidence of effective RF delivery to deep lesions with perforation. Seven clinical successes were achieved (6 complete), with the coil electrode catheters accounting for 5 of the 7, although the procedure times were shorter with the baskets. Critical lesions were those from the crista to the SVC. Planned trans-isthmus lesions were not done, but may be needed to prevent atrial flutter not seen prior to effective AF ablation. CONCLUSIONS: Special basket and coil-electrode catheters may be useful but require refinement. The finding that lesions between the crista terminalis and the SVC were critical to success may be applicable to some cases of AF in humans.

Animals↗
PubMed2001

Sinus node recovery after 25 years of atrial flutter.

This case report demonstrates that the sinus node can recover relatively quickly even after being suppressed by atrial flutter for 25 years, and that a permanent pacemaker may not always be necessary in all patients with sinus arrest after a successful atrial flutter ablation.

Aged↗
PubMed2001

Histopathological correlation of ablation lesions guided by noncontact mapping in a patient with peripartum cardiomyopathy and ventricular tachycardia.

A patient with peripartum cardiomyopathy developed a nearly incessant nonsustained VT. Guided by a noncontact mapping system, the tachycardia was mapped to the mid-septum of the right ventricle and ablated. Despite transient success, the tachycardia recurred and the patient subsequently died of multiorgan failure. Histopathological correlation of the ablation site revealed a nontransmural lesion that may have contributed to the failure of the ablation.

Adult↗
PubMed2000

Internal transcardiac pericardiocentesis for acute tamponade.

If the catheter is still in the pericardium when tamponade is recognized during catheterization or electrophysiologic procedures, it can be used for definitive aspiration and relief of tamponade. This is physiologically beneficial to the patient, and psychologically beneficial to both patient and medical staff.

Adult↗
PubMed2000

Electrophysiologic testing to identify patients with coronary artery disease who are at risk for sudden death. Multicenter Unsustained Tachycardia Trial Investigators.

BACKGROUND: The mortality rate among patients with coronary artery disease, abnormal ventricular function, and unsustained ventricular tachycardia is high. The usefulness of electrophysiologic testing for risk stratification in these patients is unclear. METHODS: We performed electrophysiologic testing in patients who had coronary artery disease, a left ventricular ejection fraction of 40 percent or less, and asymptomatic, unsustained ventricular tachycardia. Patients in whom sustained ventricular tachyarrhythmias could be induced were randomly assigned to receive either antiarrhythmic therapy guided by electrophysiologic testing or no antiarrhythmic therapy. The primary end point was cardiac arrest or death from arrhythmia. Patients without inducible tachyarrhythmias were followed in a registry. We compared the outcomes of 1397 patients in the registry with those of 353 patients with inducible tachyarrhythmias who were randomly assigned to receive no antiarrhythmic therapy in order to assess the prognostic value of electrophysiologic testing. RESULTS: Patients were followed for a median of 39 months. In a Kaplan-Meier analysis, two-year and five-year rates of cardiac arrest or death due to arrhythmia were 12 and 24 percent, respectively, among the patients in the registry, as compared with 18 and 32 percent among the patients with inducible tachyarrhythmias who were assigned to no antiarrhythmic therapy (adjusted P<0.001). Overall mortality after five years was 48 percent among the patients with inducible tachyarrhythmias, as compared with 44 percent among the patients in the registry (adjusted P=0.005). Deaths among patients without inducible tachyarrhythmias were less likely to be classified as due to arrhythmia than those among patients with inducible tachyarrhythmias (45 and 54 percent, respectively; P=0.06). CONCLUSIONS: Patients with coronary artery disease, left ventricular dysfunction, and asymptomatic, unsustained ventricular tachycardia in whom sustained ventricular tachyarrhythmias cannot be induced have a significantly lower risk of sudden death or cardiac arrest and lower overall mortality than similar patients with inducible sustained tachyarrhythmias.

Aged↗
PubMed2000

Death and readmission in the year after hospital admission with cardiovascular disease: the Hunter Area Heart and Stroke Register.

OBJECTIVES: To compare outcomes one year after hospital admission for patients initially discharged with a diagnosis of acute myocardial infarction (AMI), other ischaemic heart disease (other IHD), congestive heart failure (CHF) or stroke. DESIGN: Cohort study. SETTING: Hunter Area Heart and Stroke Register, which registers all patients admitted with heart disease or stroke to any of the 22 hospitals in the Hunter Area Health Service in New South Wales. PATIENTS: 4981 patients with AMI, other IHD, CHF or stroke admitted to hospital as an emergency between 1 July 1995 and 30 June 1997 and followed for at least one year. MAIN OUTCOME MEASURES: Death from any cause or emergency hospital readmission for cardiovascular disease. RESULTS: In-hospital mortality varied from 1% of those with other IHD to 22% of those with stroke. Almost a third of all patients discharged alive (and 38% of those aged 70 or more) had died or been readmitted within one year. This varied from 22% of those with stroke to 49% of those with CHF. The causes of death and readmission were from a spectrum of cardiovascular disease, regardless of the cause of the original hospital admission. CONCLUSIONS: Data from this population register show the poor outcome, especially with increasing age, among patients admitted to hospital with cardiovascular disease. This should alert us to determine whether optimal secondary prevention strategies are being adopted among such patients.

Aged↗
PubMed2000

Psychosocial experiences of cardiac patients in early recovery: a community-based study.

OBJECTIVE: To report on the nature, incidence and severity of problems commonly experienced by cardiac patients in the early months of recovery, and to test the hypotheses that there exist differences in the incidences of these problems depending on age and sex. METHODS: 1124 emergency cardiac patients discharged from hospital with acute myocardial infarction, unstable angina, stable angina pectoris, chronic ischaemic heart disease or heart failure were surveyed 4 months after discharge. They were asked to indicate how often during the previous 2 weeks they had experienced each of a range of feelings and problems common to cardiac patients. RESULTS: A large proportion of patients reported experiencing problems in the areas of emotional reactions (70%), physical condition (79%), convalescence (67%) and relating to family and friends (63%). Severe problems were experienced especially in the physical and convalescence areas (43% and 44%, respectively). A greater proportion of patients diagnosed with heart failure experienced problems than those with other diagnoses, and these problems were more severe. Amongst myocardial infarction patients, a greater proportion of females than males reported severe problems in the emotional and physical areas, and patients 65 years and over were more likely than younger patients to report experiencing severe problems with physical condition. CONCLUSIONS: Many cardiac patients are experiencing psychosocial problems 4 months after hospital discharge, especially with physical activities and convalescence. A knowledge of the incidence and nature of these problems may help nurses to assist patients to validate their experiences.

Adaptation, Psychological↗
PubMed2000

Lack of efficacy of 9-aminocamptothecin in adults with newly diagnosed glioblastoma multiforme and recurrent high-grade astrocytoma. NABTT CNS Consortium.

9-Aminocamptothecin (9-AC) was administered as a 72-h i.v. infusion every 2 weeks to a total of 99 adults with high-grade astrocytomas. Fifty-one patients with newly diagnosed glioblastoma multiforme received 9-AC treatment prior to radiation therapy and 48 patients with high-grade astrocytomas were treated at the time of tumor recurrence. Upon entrance into these research protocols, all patients had measurable disease that was evaluated on a monthly basis with volumetric CT or MRI scans. A partial response was defined by > or =50% reduction in the contrast enhancing volume on stable or decreasing doses of glucocorticoids. The study specified that all apparent responders would have central review of their radiologic studies and histopathology. The initial patients treated with 9-AC were also receiving anticonvulsants and were noted to have minimal myelosuppression with this chemotherapy. Thus, 9-AC doses were escalated from the previously reported maximum tolerated dose (MTD) of 850 microg/m2/24 h. We then established new MTDs for patients receiving enzyme-inducing anticonvulsants. We defined these MTDs to be 1,776 microg/m2/24 h for newly diagnosed, previously untreated patients and 1,611 microg/m2/24 h for patients with recurrent disease. Twenty-two patients with newly diagnosed glioblastoma multiforme received 9-AC at doses > or =1,776 microg/m2/24 h. Of these, 18 had evaluable disease on central review, and 0 of 18 (0%) demonstrated a partial or complete response. Twenty-one patients with recurrent high-grade astrocytomas were treated at 1,611 microg/m2/24 h; 20 had evaluable disease and 0 of 20 (0%) had a partial or complete response. Thus, the overall response rate in the 38 evaluable patients treated at the MTD was 0 of 38 (0%). Furthermore, of the 51 evaluable patients who were treated at doses less than the MTD, only one partial response was observed, yielding an overall response rate of 2%. Evidence of drug failure was rapid with tumor progression in one-half of patients after 2 drug cycles. 9-AC lacks evidence of substantial activity in patients with newly diagnosed or recurrent high-grade astrocytomas.

Adult↗
PubMed2000

Ethyl 5-methyl-4-(2,5,5-trimethyl-1, 3-dioxan-2-yl)isoxazole-3-carboxylate.

The title compound, C(14)H(21)NO(5), possesses an isoxazolyl group in the axial position of the 1,3-dioxanyl ring. The two rings are rotated about the bond joining them such that the two C(methyl)-C(dioxanyl)-C-C torsion angles are 92.1 (2) and -84.1 (2) degrees. In this conformation, neither the methyl nor ethoxycarbonyl substituents on the isoxazole are presented towards the dioxanyl chair.

Crystallography, X-Ray↗
PubMed2000

Adenosine induced atrial fibrillation precipitating polymorphic ventricular tachycardia.

An 86-year-old female developed supraventricular tachycardia 36 hours after a myocardial infarction (MI). She developed atrial fibrillation and polymorphic ventricular tachycardia (PVT) following administration of 12 mg of adenosine. The PVT caused hemodynamic instability with no response to cardioversion, but termination with procainamide. The heart is vulnerable to hemodynamically unstable, possibly lethal, PVT early after MI under some circumstances. This vulnerability may be exposed following administration of adenosine. Extra caution is warranted when using adenosine in the post-MI period.

Adenosine↗