Biomedical subjects
Publications and source records attributed to W Kelly.
This article provides historical and statistical information on the development of this service option in the State of New Jersey. It investigates Adult Day Care in the state from its inception to the present and includes the findings of a survey of thirty-four Adult Day Centers. Future planners, policymakers, funding sources and providers of service will garner much useful information for their projects.
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A retrospective review of twenty-five normal MRI brain studies performed with the spin-echo technique focused special attention on the ventricular and extraventricular cerebrospinal fluid (CSF) and revealed unique signal intensity characteristics in the two locations. In addition, MRI studies of ten patients with abnormal extraaxial fluid collections either missed with CT or indistinguishable from CSF on CT images were also analyzed. MRI is more sensitive when compared to CT in evaluating the composition of CSF. Unique signal intensity characterizes the two major CSF compartments and presumably reflects their known but subtle difference in protein concentration (10-15 mg%). Normal variant or abnormal developmental fluid collections can be better characterized with MRI than with CT. These preliminary observations are offered in view of their implications for patient management and suggest further investigation.
Kerr's hypothesis (J. Comp. Neurol., 159 (1975) 335-356) that chronic lesion of the lateral spinothalamic tract (LSTT) might cause the ventral STT (VSTT) to take over the nociceptive function of the LSTT was tested electrophysiologically in 4 cats. Recordings were made from 15 antidromically identified deep STT cells in L7 6 months after lesion of the LSTT at L1, confirming that these cells do not project rostrally in the LSTT. The receptive fields of 12 deep STT cells were studied and found to be characteristic of these cells in normal animals; they had not developed the nociceptive characteristics of lamina I STT cells. Immunohistochemistry showed that substance P-containing afferents were still contained within the dorsal laminae of the L7 grey matter. These results disprove Kerr's hypothesis and suggest that plasticity in other ascending systems must be responsible for the return of pain after lesion of the LSTT.
Lymphocytic hypophysitis has been recognized as a distinct clinicopathologic entity. It is a cause of hypopituitarism in the postpartum period and is believed to have an autoimmune pathogenesis. We treated a patient with lymphocytic hypophysitis with two unique features. First, this patient had had a prolactin level of 101 ng/mL (normal, 0 to 25 ng/mL). To our knowledge, this degree of elevation has not been previously reported and is a level that might cause confusion with prolactin-secreting pituitary adenomas. Second, this patient had positive titers for antiparietal cell antibodies in conjunction with a low vitamin B12 level and anemia. To our knowledge, this is the first report of a clinically important autoantibody to extrapituitary tissue in a living patient with lymphocytic hypophysitis.
Eighteen patients with ocular manifestations of Graves' disease were treated by plasma exchange. Detailed clinical, ophthalmological and orthoptic assessments were made including computerized axial tomography and A + B scan ultrasound of the orbits. Seventeen different ocular parameters were separately rated for each patient. The changes recorded were small, statistically insignificant, and no patient was cured of ocular disease. There were no significant correlations between the ocular changes recorded and age, sex, duration of ophthalmic symptoms, the presence of thyroid antibodies, the number of exchanges, or the concurrent administration of azathioprine.
The authors report on a series of 60 patients who underwent arterial injection-digital subtraction angiography (AI-DSA) for evaluation of suspected cerebrospinal disease. High-quality images were consistently obtained, facilitating accurate diagnosis of a wide variety of traumatic, inflammatory, and neoplastic conditions. As experience has accumulated, the AI-DSA technique has all but supplanted conventional film-screen serialography at this institution. Important advantages of AI-DSA include reduced procedural time and decreased contrast agent burden, which mean increased patient safety. Film costs can also be markedly reduced. Moreover, image quality (information content) is not significantly affected. The technique is especially useful in emergency situations, in cases where multiple arterial injections and serialograms are required, and in cases in which transcatheter embolization is carried out. We feel these considerations will insure broadened application of this diagnostic modality as the AI-DSA equipment becomes more widely available.
Locally recurrent breast cancer involving the previously irradiated chest wall and skin is a difficult but manageable problem. A detailed oncological evaluation is initially undertaken to determine the extent of local and systemic disease. Local infection, if present, is controlled by topical therapy with 0.5% silver nitrate in conjunction with well-planned, aggressive radiotherapy to the areas of tumor recurrence. Concomitant, hormonal, and/or cytotoxic chemotherapy is administered if evidence of systemic involvement is detected. Biopsies of the ulcer margin are performed with surgical excision and débridement as indicated, followed by sequential skin grafting. Seven patients are presented in whom circumferential ulcer biopsies, radiation therapy, skin grafting, and topical silver nitrate therapy were carried out with control and resolution of local symptoms in all cases. It is not essential to have initial tumor control in order to insure graft take. This program has particular application to the poor risk surgical patient, with or without evidence of systemic disease.
Twenty-two patients with the mitral valve prolapse-click syndrome and chronic ventricular dysrhythmia were judged to have either right or left ventricular premature contractions on the basis of electrocardiographic QRS configuration of the premature beats. The 11 patients with right-sided premature ventricular contractions (PVCs) were younger (P < .01), and had less abnormal electrocardiograms (NS) and fewer complications (NS) than those with left-sided PVCs. Coronary arteriograms performed on four in the latter group were normal, supporting a noncoronary etiology for the arrhythmia. Thus, patients with mitral valve prolapse and chronic ventricular dysrhythmia appear to have an equal prevalence of right- and left-sided premature complexes and, though not statistically significant, there was a consistent trend toward a more malignant course in the group with left ventricular premature complexes.
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Four crows were trained to key peck for food. Then, they were exposed to a positive response contingency that required them to peck the key when it was illuminated briefly (the trial) in order to receive food. This procedure resulted in consistent within-trial pecking. When the contingency changed so that food was presented at the end of a trial when no response occurred, but the trial terminated immediately and food was omitted when a response occurred (negative response contingency), responding decreased markedly. Eight pigeons were studied under the same change in contingencies. These birds varied in their response histories from naive to having several years' experience. The previously naive pigeons also showed rapid declines in responding under the negative contingency; the responding of the birds with extended training histories declined much more slowly. Eventually, however, six of the eight pigeons showed little or no responding under the negative contingency, while they responded consistently when re-exposed to the positive contingency. These findings question the power and the generality of the negative automaintenance phenomenon.
Key pecking for food was shaped in four crows within a conventional operant-conditioning test chamber. When pecking stabilized, a metal screen with openings 2.5 cm high by 1.0 cm wide, was placed over the response key, so that the crow could still see but could no longer peck the key. At the same time, several dozen wooden matchsticks, which could be used to operate the key, were placed in the test chamber. The crows made no use of these during 50 to 75 hr of exposure to this condition. Subsequently, the behavior of two crows was shaped so that they approached the matchsticks, picked one up in their beaks, approached the response key with the matchstick in their beak, and finally operated the response key by poking the matchstick through the screen. This shaping procedure was ineffective with the two other crows. However, these birds were successfully trained through positional fading of the tool. This involved suspending a metal rod from the ceiling so that it hung directly in front of the response key, and the crow had only to peck it to operate the key. Then, the rod was gradually lowered by lengthening its tether until it eventually rested on the floor of the test chamber. The principal advantage of this methodology is the automatic recording of the terminal (tool-using) behavior under study.
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1. A study was made of the stereospecificity of hydrogen removal in the sequential desaturations performed by intact cells of Chlorella vulgaris in the biosynthesis of oleic acid, linoleic acid and alpha-linolenic acid. 2. By use of erythro- and threo-9,10-(2)H(2)-, -12,13-(2)H(2)- and -15,16-(2)H(2)-labelled precursors, it was demonstrated that the pair of hydrogen atoms removed from each of these positions had the cis relative configuration. 3. That the hydrogen atoms removed in oleic acid and linoleic acid formation were of the d absolute configuration was proved by use of d- and l-9-(3)H-and -12-(3)H-labelled precursors. 4. The presence of a substantial kinetic isotope effect of deuterium at both positions of the putative double bond was indicated, suggesting that the mechanism of desaturation involves simultaneous concerted removal of the pair of hydrogen atoms.
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A Computational Fluid Dynamic (CFD) model of flow in a high-pressure homogenizing valve (APV Gaulin model 30CD) was developed with the Fluent software. The 2D model consists of an unstructured hexagonal mesh, dense in the regions of high gradients. The flow (single-phase) was modeled as laminar upstream of and in the channel (gap) and turbulent downstream of the channel exit. Applying a realizable kappa-epsilon turbulence model, the CFD model accurately predicted the effect of gap space on fluid dynamic conditions upstream (inlet pressure and pressure gradient) and downstream (impact pressure) of the channel for a valve with a standard (CD-0) impact distance (0.25 mm) and a 1 cP fluid. This CFD model was then used to estimate the magnitude of the fluid dynamic parameters (except cavitation effects) presumed to be responsible for cell breakage, as a function of gap space, impact distance and fluid viscosity. The CFD models predicted that for a given volumetric flowrate the upstream fluid conditions (inlet pressure gradient, maximum channel strain rate) and the maximum energy dissipation rate in the post-gap jet depend only on the gap space and the fluid viscosity and not on the impact distance. The impact pressure however depends on the gap spacing, the fluid viscosity and especially the impact distance. Experimental results indicate that higher inlet pressures are required to break cells, if the impact distance is increased. By conducting experiments to isolate individual cell breakage mechanisms for a single pass, threshold values were identified for breaking Escherichia coli cells: pressure gradient, 1.2 x 10(12) Pa/m; energy dissipation rate, 1.0 x 10(10) m(3)/s(2); and impact pressure, 160 psig. By isolating the wall impact as the sole mechanism responsible for breaking the E. coli cells between 3000 and 6000 psig inlet pressure, a relationship between E. coli cell breakage rate and maximum wall impact pressure was established (eq 5).
Furchgott and Zawadski have shown that acetylcholine (ACh) does not act directly on the smooth muscle of blood vessel walls, but rather via receptors on the endothelial cells lining the lumen, to release an endothelium-derived relaxing factor (EDRF). As it is very unlikely that neurotransmitter released from the periarterial nerves, which are confined to the adventitial-medial border, diffuses all the way through the medial muscle coat before acting on endothelial cells to release EDRF to produce vasodilatation, this discovery has been regarded as an indication of a pathophysiological mechanism, rather than a physiological one (see refs 2, 3). ACh is rapidly degraded in the blood by acetylcholinesterase, so that ACh must be released locally to be effective on endothelial cells. Here we demonstrate the immunocytochemical localization of choline acetyltransferase in endothelial cells of small brain vessels, which is consistent with the view that the ACh originates from endothelial cells that can synthesize and store it. We suggest that release of ACh following damage to endothelial cells during ischaemia contributes to a pathophysiological mechanism of vasodilation which protects that segment of vessel from further damage as well as brain cells from hypoxia.
Magnetic resonance (MR) images of 27 patients with ocular and orbital pathology were reviewed retrospectively and correlated with computed tomography (CT), funduscopic examination, and tissue histology. Disease processes were classified by location into ocular, extraconal, intraconal, optic nerve, and orbital apex. The diagnostic efficacy of MR differed at each location. MR was very sensitive in detecting ocular, extraconal, and intraconal lesions larger than 5 mm but was insensitive in imaging smaller lesions and in detecting pathology of the optic nerve. The limitations of MR were related to 7 mm slice thickness and 2.6 mm interslice gap. The diagnostic accuracy is expected to improve markedly with further developments in thin-section imaging and use of surface coils.