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Biomedical subjects

D Parker

Publications and source records attributed to D Parker.

At least 397 records · Page 22Linked to original sources
PubMedDate not supplied

Prognosis in low grade non-Hodgkin's lymphoma: relevance of the number of sites involved, absolute lymphocyte count and serum immunoglobulin level.

Eighty-eight patients with low grade non-Hodgkin's lymphoma were followed for a median period of 63 months. Sixty-eight per cent of the group were centrocytic/centroblastic B cell lymphomas by the updated Kiel classification. Fifty-one (58 per cent) of the patients were stage IV by the Ann Arbor classification. In 18 of these patients the bone marrow was the only site of extranodal involvement. Univariate survival analysis showed that the sum of involved sites was more discriminatory than Ann Arbor stage. Analysis by site of involvement showed that the liver and other intraabdominal sites were associated with worse survival than involvement of peripheral lymph nodes. Bone marrow and spleen involvement were not significantly associated with short survival. Increasing age at presentation was strongly associated with shorter survival and was also inversely correlated with serum albumin. Both low absolute lymphocyte count (< 1.0 x 10(9)/l), low serum IgG level (< 10 g/l) and low total immunoglobulins on presentation were significantly associated with short survival. Multivariate analysis showed that age, serum albumin and number of involved sites gave the best survival prediction. The sum of involved sites, immunoglobulin level and absolute lymphocyte count may be useful objective markers of prognosis in low-grade non-Hodgkin's lymphoma.

Adolescent↗
PubMedDate not supplied

Inhalable dust exposures, tasks, and use of ventilation in small woodworking shops: a pilot study.

Measures of workers' inhalable dust exposures, tasks, and ventilation use were made in five small woodworking shops prior to the start of an intervention effectiveness study aimed at lowering personal wood dust exposures. The data were used to (1) design a sampling protocol for an intervention success measure, (2) identify targets for intervention among the tasks and activities responsible for high dust levels, and (3) develop shop-level measures as tools for tailoring intervention activities. Geometric mean dust concentrations ranged from 1.6 to 9.9 mg/m3 in the five shops, with the highest levels occurring in a cabinet shop. All shops had centralized dust collection systems and workers generally used dust control on stationary tools (60-100% of the time) when it was available. Sanding with both stationary and handheld powered tools, cleaning with methods that can disperse dust (e.g., brushes, compressed air), and miscellaneous tasks were all responsible for significant personal exposures. The positive association between miscellaneous tasks and exposures probably reflects the high background levels generated by nearby processes. Sanding with both stationary tools and handheld powered tools represents the most significant influence on personal exposures in small woodworking shops. The authors conclude that pilot studies are useful tools for designing occupational health and safety intervention effectiveness studies.

Dust↗
PubMedDate not supplied

Reactogenicity, immunogenicity, and antibody persistence in adults given inactivated influenza virus vaccines - 1978.

Monovalent A/USSR/77 (H1N1) and trivalent A/USSR/77, A/Texas/77 (H3N2), and B/Hong Kong/72 influenza virus vaccines from four manufacturers were tested in 292 adult volunteers. Systemic reactions were mild and resembled those with 1976 (swine) vaccines containing similar doses (in micrograms) of viral hemagglutinin. Trivalent vaccines caused more local inflammation than did monovalent, especially in older women. Two doses containing 7 micrograms of hemagglutinin each were required to induce a titer of hemagglutinin-inhibiting antibody of greater than or equal to 40 against A/USSR/77 virus in a majority of persons with an initial titer of less than 10, but one dose containing 20 micrograms of hemagglutinin did so; even one dose containing 7 micrograms was sufficient if the initial titer was greater than or equal to 10. Vaccine-induced titers of antibody to A/USSR/77 virus fell more during the six months after vaccination in younger than in older adults; this observation suggested that prior experience with related influenza viruses alters both production and persistence of antibody after vaccination. Seroconversions to A/Texas/77 and B/Hong Kong/72 viruses were more frequent in younger than in older adults with titers less than or equal to 20 before vaccination, but the final proportion of volunteers with titers of greater than or equal to 40 was high in both groups. Standardization of dosages in terms of micrograms of hemagglutinin appeared to reduce differences in responses to vaccines of different types and sources.

Adult↗
PubMedDate not supplied

Children and war.

Explore the source record for details and available documents.

Adolescent↗
PubMedDate not supplied

Use of subatmospheric pressure to prevent progression of partial-thickness burns in a swine model.

The poorly understood, complex series of events that follows thermal injury frequently results in progressive loss of tissue. The concept of reversing this distinctive series of events has focused on the zone of stasis. Tissues in the zone of stasis that surround burn injuries usually die over a period of 48 to 72 hours postinjury, resulting in a more severe injury. Application of a controlled subatmospheric pressure (125 mm Hg) in an artificially closed space to partial-thickness burns in pigs significantly decreased the maximum depth of cellular death under the burn when the pressure was applied within 12 hours after burn creation (depth of control burns = 0.885 +/- 0.115 mm; subatmospheric pressure treated burns (0-hour delay) = 0.095 +/- 0.025 mm). A decrease in the depth of cell death was noted when subatmospheric pressure was applied for as little as 6 hours. In summary, the application of the negative pressure to partial-thickness burn injuries prevented progression of the wound to a deeper injury in this experimental pig model. A 12-hour working window exists between injury and treatment with reduced pressure, with an application time of as little as 6 hours for successful prevention of injury progression. This technique may represent a new, inexpensive, 'low tech' method for the treatment of partial-thickness burn injuries.

Animals↗
PubMedDate not supplied

Quantitation and in vitro analysis of the inflammatory cells in experimental allergic encephalomyelitis in the guinea-pig.

Inflammatory cells from the meninges of guinea-pigs with acute EAE have been isolated and quantitated. A mean of 7.5 x 10(6) cells were recovered from the brains of animals showing clinical signs of disease in contrast to only 1.5 x 10(6) cells in the controls. The immunological specificity of the meningeal inflammatory cells was determined using the lymphocyte transformation test and compared with another inflammatory cell population, the peritoneal exudate cells (PECs), in the same animal. The meningeal exudate cells responded only to the mitogen Concanavalin A (Con A) and not to the antigens myelin basic protein and tuberculin (PPD). In contrast, the PECs proliferated in the presence of both antigens and the mitogen.

Animals↗
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The effect of protecting guinea-pigs against EAE on the meningeal inflammatory cell-infiltrate.

Guinea-pigs were found to be fully protected from the clinical signs of EAE when they were given spinal cord in FIA either 3, 7. or 14 days immunization with spinal cord in FCA. If the animals were protected by the recruitment of suppressor cells then cyclophosphamide (CY) might break this protection. CY at 300 mg/kg and 20 mg/kg was given either before the protective inoculum to try to eliminate suppressor cell precursors or before immunization to eliminate the suppressors cells themselves. No clinical signs of EAE developed in any of these groups of guinea-pigs. It was found, however, that large numbers of meningeal inflammatory cells could be isolated from the brains of guinea-pigs protected from EAE when the protective inoculum was given only 1 week before immunization. These cell numbers were further significantly increased by giving CY in addition to the protective inoculum. The meningeal inflammatory cells and peritoneal exudate cells (PECs) from guinea-pigs protected against EAE were compared to those isolated from animals with acute EAE. These cells from guinea-pigs with acute EAE responded, in the lymphocyte transformation test, to the mitogen. The PECs also responded to the brain antigen, myelin basic protein (MBP) and to tuberculin (PPD). The meningeal inflammatory cells did not respond to either antigen. The PECs from animals protected against EAE responded to mitogen and PPD, but not to MBP, but the meningeal inflammatory cells did not respond to antigen or mitogen. The percentage of T lymphocytes in the meningeal inflammatory infiltrates of protected and unprotected guinea-pigs was similar, but that of phagocytic cells was significantly depressed in the inflammatory infiltrates of animals protected against EAE.

Animals↗
PubMedDate not supplied

Further modification to soft drinks to minimise erosion. A study in situ.

Soft drinks have been successfully modified to reduce enamel erosion. The aim of this study was to further modify an original low erosive blackcurrant drink product by the addition of a gum, to manipulate more favourably other drink parameters. The study was a single-blind, randomised four treatment crossover design involving 12 healthy volunteers. During 10 working-day study periods, subjects wore enamel samples in the mid palatal region of a removable appliance. Specimens were taped to expose a 2-mm enamel window. The drinks under test were: (1) Orange juice, (2) Original blackcurrant drink, (3) Water, and (4) Experimental blackcurrant drink. Drinks were imbibed at 250-ml volumes 4 times a day during appliance wearing from 09.00 to 17.00. Appliances were removed at lunchtime. Measurements of specimens were made at baseline, 2, 5 and 10 days using a profilometer. One 5-day and one 10-day specimen from each subject during each treatment were ultrasonicated. Significant differences, in erosion between drinks, were seen at days 5 and 10. Comparisons of preselected pairs of drinks of interest showed significantly reduced erosion by the two blackcurrant drinks compared to orange juice with no significant differences from water. The original blackcurrant drink produced significantly less erosion than the experimental drink. Ultrasonication removed enamel from the Orange juice specimens but very little from those exposed to water and the two blackcurrant drinks. Extrapolating the effects of both blackcurrant drinks suggested that alone they should not cause significant clinical erosion in a lifetime's intake of 1 litre per day.

Adult↗
PubMedDate not supplied

Use of sedative and analgesic agents in neurotrauma patients: effects on cerebral physiology.

Sedation and analgesia is used primarily in the intensive care unit (ICU) to limit the stress response to critical illness, provide anxiolysis, improve ventilatory support, and facilitate adequate ICU care. However, in the neurotrauma ICU there are many other reasons for the use of these agents. The primary aim is to prevent secondary cerebral damage by maintaining adequate cerebral perfusion pressures. This is accomplished in several different ways. Controlling intracranial pressure (ICP) and maintaining an adequate mean arterial pressure (MAP) is at the cornerstone of this management. Lowering the metabolic demands of the brain is also an important consideration as a treatment strategy. Analgesic and sedative agents are utilized to prevent undesirable increases in ICP and to lower cerebral metabolic demands. Concerns surrounding the use of these agents include time to awakening after discontinuation, effect on the cerebrovasculature, and the effect on patient outcome. There are many different pharmacological agents available, each with their distinct advantages and disadvantages. The purpose of this review is to evaluate the pharmacokinetic and pharmacological effects of each of these agents when used in neurotrauma patients.

Analgesics↗
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Spinal-Cord plasticity: independent and interactive effects of neuromodulator and activity-dependent plasticity.

Plasticity is one of the most extensively studied aspects in neuroscience. Interest in it has primarily been related to its proposed role in learning and memory and its relevance to adaptive changes following injury. Plasticity can be evoked by changes in molecular, cellular, and synaptic properties, either as a result of activity-dependent effects, or by relatively slow-acting neuromodulatory transmitters. In addition, it is increasingly recognized that the plasticity evoked by these individual effects can be altered by previous inputs and is thus itself plastic. Here, I will review studies in the lamprey spinal cord that have examined individual and interactive activity-dependent and neuromodulator-mediated plasticity. The results show that activity-dependent and neuromodulator-mediated plasticity evoke neuron-and synapse-specific effects at different levels in the spinal cord, and that interactions within and between these effects can evoke dynamic changes in cellular, synaptic, and network plasticity.

Action Potentials↗
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The 40 Hz modulation-following response: prediction of low-frequency uncomfortable loudness levels in normally hearing adults.

Preliminary investigations have been made in normally hearing alert adults to establish whether the 40 Hz modulation-following response (MFR) can be used to predict 400 Hz uncomfortable loudness levels (ULLs). The MFR stimulus was a 400 Hz carrier, amplitude- and frequency-modulated by a 40 Hz sine function. Subjective ULLs were obtained using standard procedures. Objective ULLs were obtained from MFR parameter intensity functions using rms amplitude, phase angle and magnitude-squared coherence (40 Hz components). The best predictions of the subjective ULL were made using objective ULLs calculated from the gradients of linear best-fit lines for individual phase-intensity functions (80 per cent predicted within 10 dB of the subjective ULL; maximum deviation=16 dB). Poorest predictions were based on inter-subject average rms amplitude-intensity functions, where as few as 14 per cent were within 10 dB of the subjective value. The best predictions were considered sufficiently accurate to warrant further investigation using a variety of modulation and carrier frequencies in different age groups and with varying degrees of hearing loss.

Adult↗
PubMedDate not supplied

Nurses' use of patient notes to chart bowel care management for the palliative care patient.

Little is known about nurses' knowledge base and practice in the provision of Bowel Care Management (BCM). Recently, a study designed to investigate both factors was conducted in two hospices, one in New South Wales and the other in South Australia. Twenty-four nurses and 100 palliative care patients participated in the study. The audit of patients' medical records, one of several research methods used in the study, will be discussed here. The research identified that in all but two cases, patients' information about their BCM practices used in the home environment was not documented on their admission to the hospice. Further, the considerable number of charts used in each hospice to record BCM generally asked for information related to bowel function and the use of pharmaceutical preparations, to the exclusion of other methods of management.

Colonic Diseases, Functional↗
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Supracondylar fractures of the femur in children.

Nonphyseal supracondylar fractures of the femur are considered to be uncommon in children and have received little attention in the literature. A retrospective review of femoral fractures in children at the authors' institution was undertaken to ascertain the incidence of supracondylar femoral fractures, the influence of associated musculoskeletal conditions, and pitfalls of management. In this study of 102 femoral fractures, there was an incidence of 12% of supracondylar fractures. Four of 12 patients had a significant predisposing musculoskeletal condition contributing to the genesis of the fracture. Five fractures were undisplaced and easily managed. Seven displaced fractures required intervention to achieve an adequate reduction. The literature is reviewed and a classification system for these fractures is presented. Treatment options are discussed and recommendations made based on this experience.

Adolescent↗
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Does central nervous system toxicity occur in transplant patients with hypocholesterolemia receiving cyclosporine?

A syndrome of severe central nervous system toxicity (confusion, cortical blindness, quadriplegia, seizures, and coma) associated with cyclosporine therapy and a low serum cholesterol level in patients with liver transplants has been described. We present a case history of a patient who demonstrated several similar features after heart-lung transplantation. Possible cyclosporine neurotoxicity should be considered in any patients with hypocholesterolemia receiving this drug.

Adult↗
PubMedDate not supplied

Persistence of the Fc cytophilic antibody receptor in macrophage hybrid cells.

Hybrid cell clones were obtained from mouse macrophase/Ehrlich ascites cell fusions which showed the 'Fc' cytophilic antibody receptor site, phagocytosis and motility typical of macrophages. With continued growth of the clones for 11 weeks, the receptor became undetectable but could be unmasked by dilute trypsin treatment; subsequent remasking of the receptor could be prevented with cycloheximide treatment of the hybrid cells. These hybrids produced cystic anaplastic tumours in neonatal irradiated mice. Chinese hamster/mouse interspecific macrophage hybrid cells did not show macrophage markers. This was probably due to rapid loss of macrophage chromosomes from the hybrid cells.

Animals↗