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Biomedical subjects

J B Moore

Publications and source records attributed to J B Moore.

At least 55 records · Page 3Linked to original sources

Proton NMR imaging of cerebral blood flow using H2(17)O.

Cerebral blood flow was quantitatively mapped by monitoring the cerebral washout of H2(17)O using rapid, single-shot proton NMR imaging. H2(17)O acts as a freely diffusible contrast agent for proton imaging via its scalar-coupled term, enhancing T2 relaxation. Measured values for CBF ranged from 29 to 106 ml/min/100 g over a range of arterial pCO2 between 23 and 81 Torr.

Animals↗

Characterization of single channel currents using digital signal processing techniques based on Hidden Markov Models.

Techniques for extracting small, single channel ion currents from background noise are described and tested. It is assumed that single channel currents are generated by a first-order, finite-state, discrete-time, Markov process to which is added 'white' background noise from the recording apparatus (electrode, amplifiers, etc). Given the observations and the statistics of the background noise, the techniques described here yield a posteriori estimates of the most likely signal statistics, including the Markov model state transition probabilities, duration (open- and closed-time) probabilities, histograms, signal levels, and the most likely state sequence. Using variations of several algorithms previously developed for solving digital estimation problems, we have demonstrated that: (1) artificial, small, first-order, finite-state, Markov model signals embedded in simulated noise can be extracted with a high degree of accuracy, (2) processing can detect signals that do not conform to a first-order Markov model but the method is less accurate when the background noise is not white, and (3) the techniques can be used to extract from the baseline noise single channel currents in neuronal membranes. Some studies have been included to test the validity of assuming a first-order Markov model for biological signals. This method can be used to obtain directly from digitized data, channel characteristics such as amplitude distributions, transition matrices and open- and closed-time durations.

Animals↗

Magnetic resonance imaging and neurobehavioral correlates in schizencephaly.

We studied three patients with schizencephaly and related the results of comprehensive neuropsychologic and speech/language assessments to the severity and location of the brain malformations as appreciated by magnetic resonance imaging. Level of general intellectual functioning related to the amount of brain tissue involved, and variations in specific neurobehavioral abilities reflected the location of the brain malformation and the prenatal onset of the disorder. The overall findings emphasize the importance of comprehensive neuropsychologic and speech/language studies for appreciating the impact of prenatal neural insult on the functional reorganization of the brain and subsequent neurobehavioral functioning.

Adolescent↗

6-Benzoxazinylpyridazin-3-ones: potent, long-acting positive inotrope and peripheral vasodilator agents.

A series of 6-benzoxazinylpyridazin-3-ones was prepared and evaluated for inhibition of cardiac phosphodiesterase (PDE) fraction III in vitro and for positive inotropic activity in vivo. 6-[3,4-Dihydro-3-oxo-1,4(2H)-benzoxazin-7-yl]-2,3,4,5-tetrahydro-5 - methylpyridazin-3-one (bemoradan) was found to be an extremely potent and selective inhibitor of canine PDE fraction III and a long-acting, potent, orally active inotropic vasodilator agent in various canine models. Additional benzoxazin-6-yl and -8-yl compounds were also prepared. Altering the pyridazinone substitution from the 6-position to the 7-position produced a 14-fold increase in the iv cardiotonic potency (ED50) from 77 to 5.4 micrograms/kg while substitution at the 8-position reduced potency. Methyl substitution at various sites in the molecule was also examined. Positive inotropic activity was maintained for between 8 and 24 h after a single oral dose (100 micrograms/kg) of bemoradan in dogs, thus making it one of the most potent and long-acting orally effective inotropes yet described. Bemoradan is currently under development as a cardiotonic agent for use in the management of congestive heart failure.

3',5'-Cyclic-AMP Phosphodiesterases↗

Conservative management of combined pancreatoduodenal injuries.

We have reviewed our recent 12-year experience in treating 62 patients with combined injuries to the pancreas and duodenum; 60 percent were the consequence of penetrating wounds and 40 percent due to blunt trauma. For analysis, grades I through V were assigned to reflect severity of injury. Grade I (16 percent) and II injuries (23 percent) were treated with simple repair and drainage. Grades III (19 percent) and IV (32 percent) were managed primarily by pyloric exclusion, whereas grade V injuries (10 percent) underwent pancreatoduodenectomy. Pancreatic and duodenal complications developed in 35 percent and 2 percent, respectively. The overall mortality was 19 percent; 83 percent died within the first 24 hours from exsanguination or severe head injury. Although no single procedure uniformly applies to the combined pancreatoduodenal trauma, active sump drainage of the pancreas, pyloric exclusion of the duodenum, and early nutritional support through needle catheter jejunostomy are the mainstay treatment principles.

Adult↗

Emergency Department thoracotomy in children--a critical analysis.

Recent clinical reviews have helped to clarify the role of Emergency Department (E.D.) thoracotomy in critically injured adults. However, guidelines in the pediatric population remain ill defined. The purpose of this report is to examine the yield of E.D. thoracotomy in patients less than or equal to 18 years of age to allow for a more cost-effective application of this heroic measure. From an 11-year experience of 689 consecutive E.D. thoracotomies, 83 patients (12%) were less than or equal to 18 years old. Mechanism of injury was blunt trauma in 57%, gunshot wound in 30%, and stab wound in 13%. Mean age was 15 years and 71% were male. Survival by injury mechanism was 9% (1/11) for stab wound, 4% (1/25) for gunshot wound, and 2% (1/47) for blunt trauma. Sixty-nine patients presented to the E.D. without vital signs and only one, a 16-year-old with stab wounds to the chest and abdomen, survived. In contrast, two (14%) among 14 patients presenting with vital signs were salvaged. As in adults, outcome was largely determined by injury mechanism and physiologic status on E.D. presentation. Blunt trauma, the predominant mechanism of lethal injuries in children, had a dismal outcome, with only 2% salvage and no survivors when vital signs were absent. This study demonstrates a similar outcome for E.D. thoracotomy in children compared to adults, and supports a selective policy of liberal use in penetrating injury irrespective of physiologic status but limited in those arriving lifeless following blunt trauma.

Adolescent↗

Development of an instrument to measure mothers' performance of self-care activities for children.

One who performs self-care activities for another is known as a dependent care agent, according to Orem. Attempts to study mothers' performance of self-care activities for children have been impeded by the lack of an instrument with which to measure dependent care agent performance. Findings based on a sample of 475 women indicate that the Dependent Care Agent (DCA) questionnaire developed in this study had a coefficient alpha of .91, with item-total correlations ranging from .27 to .63. Although Orem's expected dimensions of universal, developmental, and health deviation requisites were not represented in the factor analysis, individual requisites for self-care were clearly present.

Adult↗

Introduction to magnetic resonance imaging.

Magnetic resonance imaging (MRI) has become an important diagnostic tool with a wide variety of clinical applications. This article provides a qualitative description of physical principles of MRI fundamental to an appreciation of the capabilities and limitations of this complex technology. The same physical principles are used to explain the appearance of the images and the ability of MRI to provide spectroscopic data. Contrast agents, types of MRI equipment, and the safety of MRI in carrying out patient population goals are discussed. This article provides background knowledge for two subsequent articles which cover clinical application of MRI in greater detail.

Humans↗

Current indications for magnetic resonance imaging.

Magnetic resonance is a well-established imaging modality for CNS, but it's utility for visualizing the rest of the body has not been appreciated fully or exploited yet. The authors believe that MRI will become one of the primary imaging modalities for the body during the next several years. Current and future indications for magnetic resonance imaging of the body are discussed.

Adult↗

Magnetic resonance imaging in the CNS.

This article, aimed toward the nonneurologist specialist, presents current indications for MRI in the CNS. Primary and metastatic brain tumors, white matter disease, stroke and hemorrhage, hydrocephalus, and spinal disease are discussed. Emphasis is placed on the contribution of MRI to the evaluation of these major classes of disease. Because of its improved sensitivity and noninvasiveness, in most instances MRI is the initial imaging procedure of choice in the CNS.

Adolescent↗

MRI in multifocal eosinophilic granuloma: staging disease and monitoring response to therapy.

Multifocal eosinophilic granuloma is part of the spectrum of histiocytosis X, in which the unifying feature is the proliferation and infiltration of histiocytes. Central nervous system (CNS) involvement has a predilection for the hypothalamic nuclei, and these infiltrates appear as high signal foci on T2-weighted magnetic resonance (MR) images that completely resolve after effective chemotherapy. Intradiploic skull lesions are well delineated with MRI, and the relation to underlying brain may be confidently assessed. MRI is the procedure of choice for staging multifocal eosinophilic granuloma in the skull and CNS, as well as for monitoring response to therapy.

Antineoplastic Combined Chemotherapy Protocols↗

Synthesis of (aryloxy)alkylamines. 2. Novel imidazo-fused heterocycles with calcium channel blocking and local anesthetic activity.

A series of imidazo-fused heterocycles substituted with an aryloxy)alkylamine side chain were prepared as modifications to butoprozine (I) and found to possess calcium channel blocking activity similar in potency to that of bepridil in trachea smooth muscle and similar to that of verapamil in nitrendipine binding affinity in rabbit cardiac muscle. Of the various imidazo-fused heterocycles prepared, the imidazo[1,2-a]pyridines were also found to be potent local anesthetic agents. While most compounds in this series were equipotent to lidocaine in our initial screen, compounds 2 and 35 showed local anesthetic activity approximately 100 times more potent than lidocaine in our preliminary assays. These compounds represent a novel structural class of local anesthetic agents, and compound 2 is under further investigation.

Amines↗

Cardiotonic agents. Synthesis and inotropic activity of a series of isoquinolin-3-ol derivatives.

A series of isoquinolin-3-ol derivatives (II) was prepared as analogues of the clinical cardiotonic agent bemarinone (ORF 16600, I). Although in many respects the structural requirements for the cardiotonic activity of II are similar to those of bemarinone, certain differences between the series were noted. Our structure-activity studies show that II is less sensitive to alkoxy-substitution effects than is I, and more significantly, 4-substitution of II by alkyl groups, halogen, or alkanecarboxylic acid derivatives enhances cardiotonic activity in II in contrast to I, wherein analogous substitution eliminated activity. A linear correlation between contractile force (CF) increase and cyclic nucleotide phosphodiesterase fraction III (PDE-III) inhibition by the title compounds was determined. The isoquinoline derivatives were characteristically short-acting cardiotonic agents with good potency and selectivity.

Animals↗

Effects of assertion training and first aid instruction on children's autonomy and self-care agency.

Strategies for promoting autonomy and a self-care agency in children were investigated in this study. Ninety-two fifth grade students were randomly assigned to one of four learning groups: assertion training; first aid instruction; assertion/first aid; and control. Results showed mixed support for autonomy being higher where either or both assertion training and first aid instruction had occurred, and support for self-care agency being higher where first aid instruction had occurred.

Assertiveness↗