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Biomedical subjects

D A Murphy

Publications and source records attributed to D A Murphy.

At least 91 records · Page 5Linked to original sources
PubMed1992

Acquired immunodeficiency syndrome/human immunodeficiency virus risk behavior among gay men in small cities. Findings of a 16-city national sample.

BACKGROUND: Most research on acquired immunodeficiency syndrome has been conducted in several of the country's largest cities, and little is known about the current level of human immunodeficiency virus risk taking among gay men in other geographical areas. The purpose of this study was to determine the frequency of risk behavior practices among gay men in smaller communities. METHOD: A large sample of men who patronized gay bars in 16 small and moderate-size cities drawn from six states in four different regions of the country was surveyed to determine the frequency of high-risk behavior and factors influencing risk taking. Eighty-five percent of men in all cities' bars completed all survey measures. The community samples were 1991 men; mean age, 31.3 years; mean education, 10.6 years; 90% were white and 10% were of other ethnicities. All participants provided detailed information on their sexual behavior practices over the preceding 2 months and completed measures assessing their perceived peer norms concerning safer sex practices and risk avoidance, intentions to avoid risk, personal risk estimation, acquired immunodeficiency syndrome risk knowledge, perceived threat of acquired immunodeficiency syndrome/human immunodeficiency virus, and serostatus testing history. RESULTS: High-risk patterns were still common among gay men in these smaller cities; nearly one third of all men had engaged in unprotected anal intercourse an average of eight times in the past 2 months, usually outside monogamous relationships. High-risk behavior was most strongly associated with beliefs that safer sex practices would not be well accepted by peers, weak intentions to use condoms, underestimation of personal vulnerability to the acquired immunodeficiency syndrome, younger age, and higher levels of overall sexual activity. Nine percent of men tested said they were seropositive. CONCLUSIONS: Growing human immunodeficiency virus prevalence and continued high rates of risk behavior indicate that a new "front line" for human immunodeficiency virus prevention among homosexually active men has shifted to the country's smaller cities. Community prevention efforts in these areas are urgently needed to avert sharp increases in future human immunodeficiency virus infections in this population.

Acquired Immunodeficiency Syndrome↗
PubMed1992

A needs assessment survey of HIV-infected patients.

Few studies have surveyed HIV-infected patients to determine how adequately medical, legal, psychological, social service, and financial needs are being met through current treatment services. Fifty HIV-infected men seen at a county medical facility were surveyed to determine which of 17 needs were being met and the importance rating attributed to those needs. Five needs were reported by more than 30% of the sample as not being met: 1) being able to talk about fears of the future, illness, or death; 2) being occupied and having things to do; 3) having up-to-date information about HIV; 4) having someone to help them with their feelings of depression, helplessness, anxiety, or anger; and 5) help for the patient's family. Three of these five needs involve better access to psychological services. Although patients felt they had knowledgeable medical staff and good health care, they wanted more up-to-date information on HIV treatment.

Adult↗
PubMed1992

Influences of cardiopulmonary bypass, temperature, cardioplegia, and topical hypothermia on cardiac innervation.

The effects of normothermic and hypothermic cardiopulmonary bypass, crossclamping of the aortic root, cold cardioplegia, as well as epicardial application of iced slush, on the efficacy of the efferent sympathetic nervous system to augment the heart and the efferent parasympathetic nervous system to depress the heart were studied in anesthetized dogs. Cardiac rate and force are augmented by stimulation of the intrathoracic efferent sympathetic nervous system and reduced by stimulation of the intrathoracic efferent parasympathetic nervous system. After cardiopulmonary bypass, which included systemic and topical hypothermia, aortic crossclamping, and crystalloid cardioplegia, the augmentor effects of the efferent sympathetic nervous system were obtunded whereas the depressor effects exerted by the efferent parasympathetic nervous system were not. Direct cardiac myocyte augmentor responses induced by isoproterenol were unaffected by these interventions. Normothermic cardiopulmonary bypass, hypothermic cardiopulmonary bypass, crossclamping of the aorta, or cold cardioplegia did not result in blunting of the efferent sympathetic cardiac nervous system. Significant blunting of cardiac augmentation induced by the efferent sympathetic nervous system occurred after topical application of iced slush alone. These data demonstrate that blunting of the efferent sympathetic, but not parasympathetic, innervation of the heart occurs after cardiopulmonary bypass, which presumably is primarily due to altering the function of subepicardial efferent sympathetic axons by topical hypothermia and not due to altered cardiac myocyte function. These data imply that after cardiopulmonary bypass involving the procedures described, the ability of the efferent sympathetic nervous system to support cardiac rate and force is transiently impaired.

Animals↗
PubMed1991

Effects of background anger, provocation, and methylphenidate on emotional arousal and aggressive responding in attention-deficit hyperactivity disordered boys with and without concurrent aggressiveness.

We investigated the effects of background anger, provocation, and methylphenidate on emotional, physiological, and behavioral responding in children with attention-deficit hyperactivity disorder (ADHD) with and without concurrent aggression. Our study revealed that ADHD boys showed more emotional and physiological distress when exposed to an interaction in which an administrator chastised each boy's favorite counselor, compared to a friendly interaction between the two adults. The background anger manipulation did not affect the aggressive behavior of the boys against an opponent in an aggressive game. High-aggressive (HA) ADHD boys were more likely to respond to provocation with aggression than low-aggressive (LA) ADHD boys, but only LA boys showed increased physiological reactivity with increasing provocation. Methylphenidate resulted in increased heart rates under all conditions and did not interact with any of the other findings.

Adult↗
PubMed1991

Cognitive enhancing actions of PD123177 detected in a mouse habituation paradigm.

The anxiolytic-like and cognitive enhancing potential of PD123177, a non-peptide with selectivity for the angiotensin II-2 receptor recognition site, was assessed in a mouse light/dark aversion test and habituation test, respectively. PD123177 (0.01 ng kg-1 to 1.0 mg kg-1 i.p.) failed to alter the behavioural repertoire of animals in the light/dark aversion test. In contrast, daily administration of PD123177 (10.0 ng kg-1 i.p. b.d.) enhanced the performance of mice in a habituation test. In addition, PD123177 overcame the cognitive impairment induced by the administration of scopolamine (0.25 mg kg-1 i.p.). Such findings indicate for the first time a functional role for the angiotension II-2 receptor and further implicate the angiotensin system in the modulation of cognitive processes.

Angiotensin II↗
PubMed1991

Atrioventricular canal defects: results of repair in the current era.

Between December 1986 and December 1990, 37 consecutive patients underwent repair of complete atrioventricular (AV) canal with the two-patch technique. Mean age at repair was 22 months and 51% were less than 1 year of age. Eighteen (48.6%) had undergone previous palliative operations. Two operative deaths (5.4%) occurred and another patient died in-hospital for an early mortality of 8.1%. One late death (2.9%) has occurred from a respiratory infection. Actuarial survival is 87.7% at 3 years. Small size (p less than 0.05), unbalanced ventricular size (p less than 0.05), New York Heart Association (NYHA) Class IV (p less than 0.05), and severe preoperative AV valve insufficiency (p less than 0.05) were significant preoperative risk factors for death. Five survivors (14.7%) required reoperation for severe AV valve insufficiency (two) or patch leaks (three). The risk for reoperation was increased in non-Down's patients (p less than 0.02). All survivors are in NYHA Class I (93%) or II (7%). The risk for early AV valve insufficiency was increased in patients who did not have the cleft sutured (p less than 0.05), and in those with unbalanced ventricles (p less than 0.01). Risk of late AV valve insufficiency was increased only by small size (p less than 0.02). Previous pulmonary artery banding did not increase the risk of repair or of postoperative AV valve insufficiency. Complete AV canal can be repaired with low mortality. Pulmonary artery banding may still have a role to play in the very small (4-5 kg) infant in refractory heart failure.

Aortic Valve Insufficiency↗
PubMed1991

Idiopathic dilatation of the aorta with dissection in a family without Marfan syndrome.

Dissection of the aorta is very rare in children, but classically occurs in the presence of Marfan syndrome or other connective tissue disorder. We present a case of spontaneous dissection in a 12-year-old boy whose half brother has an idiopathic dilated aorta and whose mother has also required surgery for dissection of a dilated aorta. No features of connective tissue disorder were present in any family member.

Adult↗
PubMed1990

Modification of supraventricular tachyarrhythmias by stimulating atrial neurons.

The effects of stimulating the right atrial ventral ganglionated plexus on ventricular performance during atrial tachycardia was studied in 8 lightly sedated (pentobarbital, 2.5 mg/kg intravenously) dogs with sterile pericarditis. Atrial arrhythmias were induced by electrical stimulation (10 V, 4 ms, 100 Hz) of the right atrium through previously inserted temporary bipolar pacemaker wires. Various types of supraventricular tachycardias were produced. Atrial fibrillation was produced in 3 dogs, atrial tachycardia in all 8 dogs, different atrioventricular nodal ectopic rhythms in 6 dogs, and atrial flutter in 1 dog. These arrhythmias were associated with irregular ventricular contractions that resulted in low ventricular pressures during many cardiac cycles such that low or no aortic pressure was generated. Right atrial ventral ganglionated plexus stimulation induced slowing of ventricular rate so that every ventricular contraction resulted in aortic pressure generation, thus increasing mean aortic pressure. Responses elicited by atrial ganglionated plexus stimulation were eliminated after atropine administration. We conclude that electrical stimulation of the right atrial ventral ganglionated plexus results in slowing of ventricular contractile rate during supraventricular tachycardia, presumably by activating efferent vagal neuronal elements, thereby improving ventricular performance. If applicable in humans, this technique may be of use in management of postoperative atrial arrhythmias after cardiac operations.

Animals↗
PubMed1990

Anxiolytic-like action of DuP753, a non-peptide angiotensin II receptor antagonist.

The potential of DuP753, an angiotensin II receptor antagonist, to inhibit the suppressed behaviour of mice in a light/dark aversion test was investigated. The aversive response to the light compartment of the apparatus was reduced (increase in latency to move from the light to the dark compartment and decreases in rears, line crossings and percentage of time spent in the dark compartment) following treatment with DuP753 (0.1-1000 micrograms kg-1 p.o., 45 min before the test). These results further implicate the modulation of mental function by angiotensin II.

Angiotensin II↗
PubMed1990

Cardiac responses to electrical stimulation of discrete loci in canine atrial and ventricular ganglionated plexi.

The purpose of the present study was to examine cardiac effects induced by electrical stimulation (1-4 V, 1 ms, 200 Hz) of discrete loci within the ganglionated plexi located on canine atria and ventricles. When 20 loci in the right atrial ventral ganglionated plexi of 11 anesthetized open-chest dogs were stimulated, bradycardia and/or right and left atrial force suppression occurred when, on average, 15% of these loci were stimulated. Bradycardia and atrial force suppression were elicited when, on average, 8% of 15 loci in the left atrial ventral ganglionated plexi of eight dogs was stimulated. When these loci were restimulated after acute decentralization, cardiac responses were attenuated or occasionally eliminated. After atropine (1 mg/kg iv) administration, repeat stimulation of loci in the right but not left atrial ganglionated plexus induced tachycardia. Stimulation of loci in the right ventricular ganglionated plexus after the subsequent administration of desipramine (1 mg/kg iv) in six dogs resulted in an increase in right ventricular conus intramyocardial pressure. After hexamethonium administration (10 mg/kg iv, followed by a continuous infusion of 1 mg.kg-1.min-1), sympathetic responses were no longer elicited from one of the five dogs in which loci in the right atrial ganglionated plexi and from two of the six dogs in which loci of the right ventricular ganglionated plexus had elicited responses. We conclude that atrial and ventricular ganglionated plexi contain efferent parasympathetic, efferent sympathetic, and afferent neurons.

Animals↗
PubMed1990

Relative efficacy of long-acting stimulants on children with attention deficit-hyperactivity disorder: a comparison of standard methylphenidate, sustained-release methylphenidate, sustained-release dextroamphetamine, and pemoline.

Twenty-two children with attention deficit-hyperactivity disorder underwent a double-blind, placebo-controlled, crossover evaluation of the efficacy of standard methylphenidate twice a day and comparable doses every morning of a sustained-release preparation of methylphenidate (SR-20 Ritalin), a sustained-release form of dextroamphetamine (Dexedrine Spansule), and pemoline. The children were participating in a summer treatment program in which they engaged in recreational and classroom activities. Dependent measures include evaluations of social behavior during group recreational activities, classroom performance, and performance on a continuous performance task. Results revealed generally equivalent and beneficial effects of all four medications. Dexedrine Spansule and pemoline tended to produce the most consistent effects and were recommended for 10 of the 15 children who were responders to medication. The continuous performance task results showed that all four medications had an effect within 2 hours of ingestion, and the effects lasted for 9 hours. The implications of these results for the use of long-acting stimulant medication in children with attention deficit-hyperactivity disorder are discussed.

Adolescent↗
PubMed1989

Attention-deficit hyperactivity disordered boys' evaluations of and attributions for task performance on medication versus placebo.

The present study examined the effects of stimulant medication on the self-evaluations of and attributions for task performance of 26 attention-deficit hyperactivity disordered boys. Each boy performed a continuous performance task twice, once while on medication and once while on placebo. Immediately following the completion of the task, the boys were asked a series of questions concerning their self-evaluations of, and attributions for, their performance. Two findings of note were obtained. First, medication, compared with placebo, increased the correspondence between the boys' self-evaluations and their performance. Second, the boys did not use medication as a frequent explanation for their performance, as others have predicted. In fact, the boys picked medication as an explanation for their successes significantly less often than either effort or ability.

Achievement↗
PubMed1989

Surgical repair of stenotic ostial lesions of the left main coronary artery.

Fourteen patients with isolated stenosis of the left coronary artery ostium underwent vein patch angioplasty. An anterior approach between the aorta and pulmonary artery to expose the left main coronary ostium was used in 12 of 14 patients. There were no deaths, and postoperative angiograms in 13 of the patients showed normal coronary ostial contour with normal runoff. Two perioperative myocardial infarctions were observed. Four of the 14 patients underwent an urgent operation. Isolated coronary ostial stenosis appears to be a distinct clinical entity occurring in younger patients, mostly female, and often with a short clinical course. Unstable pain and hemodynamics are observed. The common pathologic cause of the stenotic lesion is not clear.

Adult↗
PubMed1988

Isolated infundibuloarterial inversion (S,D,I): a newly recognized form of congenital heart disease.

A newly recognized form of congenital heart disease is presented that is characterized by viscero-atrial situs solitus (S), D-loop ventricles (D), and inverted normally related great arteries (I), the segmental combination being (S,D,I). This anomaly may be called isolated infundibuloarterial inversion because only the subsemilunar infundibulum and the great arteries are inverted, whereas the atrial and the ventricles are not. All three patients had atrioventricular concordance, ventriculoatrial concordance, dextrocardia, superoinferior ventricles, crisscross atrioventricular relations, underdevelopment of the right ventricle, a large ventricular septal defect, and an inverted tetralogy of Fallot type of malformation of the infundibulum and great arteries. The condition known as crisscross atrioventricular relations was found in these three patients to be a major ventricular malposition characterized by marked clockwise rotation of the ventricles, as seen from the front. Two of these three cases were diagnosed accurately and repaired successfully.

Angiocardiography↗