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Biomedical subjects

J Peterson

Publications and source records attributed to J Peterson.

At least 163 records · Page 9Linked to original sources

The Department of Veterans Affairs Optical Patient Card Workstation.

The Department of Veterans Affairs has developed an optical patient card application which will undergo alpha testing in 1991. The optical cards are carried by patients and contain administrative, clinical, and image information. An optical patient card workstation (OPCW) will read/write these cards and pass this information to the VA Decentralized Hospital Computer Program (DHCP), the VA's health care information system. The intent of this work is to study the potential benefits of this technology to the VA's distributed health care network, with a large mobile patient population. It is hoped that the use of optical cards and the OPCW will enhance clinicians ability to work with a timely composite health record, and expedite the administrative workload of the medical center.

Computer Communication Networks↗

Nakahara Memorial Lecture. Pathways of carcinogenesis--genetic and epigenetic.

Considerable experimental evidence has developed to argue that carcinogenesis occurs in a series of stages whose characteristics allow division into the distinct stages of initiation, promotion, and progression. The stage of initiation results from subtle genetic alterations in individual target cells caused both by experimental perturbations as well as by ambient environmental factors. Initiation of a cell may result from the mutation of one or a few key genes whose expression is modified by many other genes. Promoting agents induce the clonal development of initiated cells susceptible to the proliferative effects of the specific promoting agent. The stage of progression is characterized by evolving karyotypic instability and may be induced by specific clastogenic effects and/or agents, the latter termed progressor agents. Carcinogens may induce cancer by an action at all three stages or selectively by an action at any one or two of the individual stages of carcinogenesis. Cancer then develops as a result of fortuitous, endogenous, or ambient environmental factors, thus accounting for the action of both genotoxic and nongenotoxic agents as carcinogens.

Animals↗

Flecainide toxicity in a neonate with supraventricular tachycardia.

Class IC antiarrhythmic drugs, specifically encainide and flecainide, have been used with increasing frequency in children and young adults with both atrial and ventricular tachyarrhythmias. As a result of the recent findings from the Cardiac Arrhythmia Suppression Trial (CAST) study, their use in adults as well as children has been questioned. Because of their potential and often dangerous side effects, the child receiving a class IC drug must be monitored very closely. We report a case of flecainide toxicity in a 2 1/2-week-old neonate who was being treated for incessant supraventricular tachycardia.

Electrocardiography↗

Psychiatric rating scales in diagnostic assessment and clinical treatment.

This chapter provides a summary and review of the current and most frequently used clinical rating scales, and discusses their specific use and application in the treatment setting. The review includes some comparison of the essential benefits of each instrument and their potential usefulness in dealing with special populations.

Anxiety Disorders↗

Inherited predisposition to alcoholism: characteristics of sons of male alcoholics.

Sons of male alcoholics (SOMAs) are at markedly heightened genetic risk for the development of alcohol abuse. Study of SOMAs could therefore conceivably increase the efficiency of research aimed at uncovering those heritable factors that predispose to alcoholism. SOMAs manifest observable behavioral, cognitive, and psychophysiological abnormalities while sober and react idiosyncratically to alcohol intoxication. They are most commonly described as conduct disordered and hyperactive, appear heir to a variety of deficits in verbal and abstract cognition, and perform more poorly in the academic environment. SOMAs are characterized by abnormal patterns of cued psychophysiological response, and appear more sensitive to the putatively reinforcing aspects of alcohol intoxication. Various methodological weaknesses permeate the relevant literature. Some straightforward improvements are suggested.

Adolescent↗

Fatty acid control of lipoprotein lipase: a link between energy metabolism and lipid transport.

Lipoprotein lipase (LPL) catalyzes the flux-generating step in transport of fatty acids from lipoprotein triacylglycerols into tissues for use in metabolic reactions. In vitro studies have shown that fatty acids can bind to the enzyme and impede its other interactions. In this study we have searched for evidence of fatty acid control of LPL in vivo by rapid infusion of a triacylglycerol emulsion to healthy volunteers. During infusion the activity of LPL but not of hepatic lipase increased in plasma, but to different degrees in different individuals. The time course for the increase in LPL activity differed from that for triacylglycerols but followed the plasma levels of free fatty acids. This was true during infusions and when the emulsion was given as a bolus injection. In particular there were several instances when plasma triacylglycerol levels were very high but free fatty acids and LPL activity remained low. Model studies with bovine LPL showed that fatty acids displace the enzyme from heparin-agarose. We suggest that in situations when fatty acids are generated more rapidly by LPL than they are used by the local tissue, they cause dissociation of the enzyme from its binding to endothelial heparin sulfate and are themselves released into circulation.

Adult↗

Magnetic resonance imaging of knee menisci. Comparison of spin echo pulse sequences.

Magnetic resonance imaging (MRI) is accurate in evaluating meniscal tears using spin echo pulse sequences. The purpose of this study was to systematically compare T1-weighted pulse sequences to two echo proton density/T2 (2eT2)-weighted sequences. Menisci were separated into four grades based on signal characteristics. In addition, all menisci were graded as positive or negative for tear. Twenty-three patients (46 menisci) were studied with both pulse sequences and the results were compared with arthroscopic findings. Using T1 sequences, 14 of 18 torn menisci and 26 of 28 untorn menisci were identified. Using 2eT2 sequences, 13 of 18 torn menisci and 26 of 28 untorn menisci were correctly identified. There was high correlation between T1 and 2eT2 sequences for torn versus untorn menisci and for grade of injury (P = .99). There is very little difference between T1- and 2eT2-weighted pulse sequences in evaluation of meniscal tears.

Arthroscopy↗

Spontaneous histamine release from washed leukocytes and whole blood in atopic and non-atopic individuals.

The ability of basophils from patients with allergic rhinitis, extrinsic asthma, chronic idiopathic urticaria and atopic dermatitis to release histamine spontaneously in vitro was studied. Spontaneous release in the presence and absence of 30% D2O was investigated from both washed leukocytes and whole blood. Compared with controls histamine release (HR) from washed leukocytes was significantly enhanced in allergic rhinitis patients only, whereas in the other groups only a certain percentage of patients was found to have high spontaneous HR. In whole blood experiments HR in all groups was within the normal range. Our data indicate that enhanced spontaneous mediator release from washed basophils in vitro does not necessarily prove this mechanism to be of pathophysiological relevance in vivo.

Adolescent↗

Frameshift mutation in exon 3 of the lipoprotein lipase gene causes a premature stop codon and lipoprotein lipase deficiency.

Several mutations in the human lipoprotein lipase (LPL) gene have been shown to underlie LPL deficiency. These mutations occur in patients who are mainly of European descent, and comprise a single base transition causing a premature stop codon, four separate amino acid substitutions and two large gene rearrangements. Together they account for approximately 40% of the LPL alleles in a cohort of 50 patients whose DNA has been examined in this laboratory. We now report on a new mutation in exon 3 of the LPL gene from a South African subject of South-east Asian extraction. This mutation comprises a six base-pair insertion at the site of a single base deletion. The net insertion of five base-pairs at amino acid positions 102 to 103 causes a shift in the reading frame, generating 44 amino acid residues of random sequence and a premature stop codon within exon 4. This mutation is predicted to result in the synthesis of a markedly truncated protein and is the cause of the enzyme deficiency in our patient.

Adult↗

Giant-cell arteritis of the uterus with associated temporal arteritis: a case report.

Giant-cell arteritis involving the uterus was identified incidentally upon hysterectomy and anterior colporrhaphy for uterine prolapse. Subsequently, the patient was found to have giant-cell temporal arteritis presenting with fever of unknown origin. Fourteen previous cases involving the female genital tract have been reported. There appears to be an association between constitutional symptoms of fever, weight loss, malaise, headache, and polymyalgia rheumatica in elderly women with uterine prolapse and giant-cell arteritis of the genital tract. The rare presentation of giant-cell arteritis in the female genital tract does not support invasive costly evaluation in asymptomatic patients. However, a thorough investigation for involvement of other sites, including appropriate treatment for generalized disease, should be undertaken.

Aged↗

Interleukin-2 (rIL-2)-induced lymphokine-activated killer (LAK) cells and their precursors express the VGO1 antigen.

Precursor and effector cells of recombinant interleukin-2 (r-IL-2)-induced lymphokine-activated killer (LAK) activity were investigated for their expression of VGO1. Peripheral blood lymphocytes (PBL) from normal donors were purified and separated in a FACS 420 into VGO1+- and VGO1- cell fractions before and after culture for 96 hr with 100 U/ml of r-IL-2. Their lytic activity against K 562 and Daudi cells was measured in a 51Cr release assay. The majority, if not all, of the LAK effector and precursor cells was VGO1+ lymphocytes. The expression of VGO1 by LAK precursor cells remained stable under the culture conditions used in our experiments. VGO1- lymphocytes cultured with r-IL-2 demonstrated neither LAK-induced activity nor expression of VGO1 antigen.

Antigens, Surface↗

Autonomic hyperreactivity and risk for alcoholism.

1. Studies which illustrate autonomic hyperreactivity in sons of alcoholics are reviewed and discussed. This response is elicited by a wide range of stimuli which vary from the stressful to the incidental. It also occurs independently of coping strategy. This hyperreactivity, which is particularly characteristic of multigenerational sons of alcoholics is significantly dampened by alcohol. This pattern of results supports a negative reinforcement model of alcohol abuse in these individuals.

Alcoholism↗

The continent gastrostomy.

In an attempt to facilitate long-term care and patient acceptance of gastrostomy feeding, the technique of permanent Janeway gastrostomy was modified. Using an auto-stapling device, a full-thickness gastric tube (6 cm long and 1.5 cm in diameter at its base) is created from the anterior wall of the stomach, based on the greater curve, with special attention to its vasculature. The base is invaginated into the stomach wall to create a tight valve. After skin closure, the terminal 1 cm is excised and the mucosa is sutured flush with the skin. A #10 French tube is inserted and positioned perpendicularly. A gastrostomy thus created will allow intermittent cannulation without leakage of gastric contents. Results of this procedure in 26 patients show a postoperative wound infection incidence of 3.8 per cent. With a mean follow up of 257 days, the gastrostomy was continent in 87 per cent of patients.

Gastrostomy↗

Trifluoperazine plasma levels and clinical response.

The authors studied 36 acutely psychotic inpatients who were diagnosed as having either a schizophrenic (N = 30) or other psychotic (N = 6) disorder. After a washout phase averaging 18 days, all patients were placed on trifluoperazine 5 mg orally twice a day. Plasma levels of trifluoperazine were obtained on days 11 and 15 of treatment and then compared with clinical response. After 2 weeks of treatment an inverted U-shaped relationship was found between change scores on the Brief Psychiatric Rating Scale and trifluoperazine plasma levels.

Adult↗

Long-term prognosis of patients undergoing electrophysiologic studies for syncope of unknown origin.

Long-term prognosis was determined in 70 patients with unexplained syncope who underwent electrophysiologic testing between April 1981 and April 1986. The electrophysiologic study had positive results in 37 patients--31 with ventricular tachycardia, 3 with supraventricular tachycardia and 3 with abnormal conduction. There was no significant difference in the 3-year actuarial recurrence rate between the positive and negative outcomes (32 vs 24%, respectively). At 3 years, patients with positive outcomes had higher rates of sudden death than patients with negative results (48 vs 9%, respectively, p less than 0.002). The 3-year total mortality rate was also markedly higher in patients with positive results than among those with negative outcomes (61 vs 15%, respectively, p less than 0.001). Multivariate analyses showed mortality to be independently associated with unsustained ventricular tachycardia on prolonged electrocardiographic monitoring. It was concluded that patients with electrophysiologically positive results had high rates of sudden death and total mortality that have not been previously well recognized.

Bundle-Branch Block↗