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Simpson DA, Blumbergs PC, McLean AJ, Scott G. Head injuries in infants and children: measures to reduce mortality and morbidity in road accidents. World J Surg 1992; 16:403-9. [PMID: 1589973 DOI: 10.1007/bf02104439] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the 6-year period from 1983 to 1988, 12 infants (less than 24 months of age) and 103 children (2 to 14 years of age) were killed in road crashes in South Australia. This represents an annual incidence of 6.4 deaths per 100,000 children at risk. At least 4 other children were killed in off-road vehicle-related accidents. Of these deaths, approximately half were car passengers, one third pedestrians, and one sixth pedal cyclists. Most of these infants and children died at the accident site or soon after, but 26 of them survived long enough to be admitted to hospitals with neurosurgical units and an audit of these patients suggests that there were at least 3 preventable deaths. However, autopsies of 78 patients show that the great majority of these deaths resulted from devastating brain and/or trunk visceral injuries. Better emergency care and the use of neurosurgical retrieval teams may save some lives. But more lives might be saved by the use of appropriate restraints for infants and children in cars, by reducing the exposure of child pedestrians and cyclists to road traffic, and by mandatory use of helmets by child cyclists. Off-road vehicular accidents are not as a rule included in road crash statistics; the practice of giving small motorcycles to young children has created a new category of vehicular accidents sometimes causing severe head injury.
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Al-Malaika S, Ibrahim AQ, Rao MJ, Scott G. Mechanisms of antioxidant action: Photoantioxidant activity of polymer-bound hindered amines. II. Bis acrylates. J Appl Polym Sci 1992. [DOI: 10.1002/app.1992.070440719] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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328
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Al-Malaika S, Coker M, Smith PJ, Scott G. Mechanisms of antioxidant action: Nature of transformation products of dithiophosphates. II. Antioxidant action of thiophosphoryl disulphides. J Appl Polym Sci 1992. [DOI: 10.1002/app.1992.070440720] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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329
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Richardson MD, Scott G, Shankland GS. Effect of cilofungin on phagocytosis and intracellular killing of Candida albicans by human neutrophils. Eur J Clin Microbiol Infect Dis 1992; 11:22-6. [PMID: 1563379 DOI: 10.1007/bf01971266] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of a beta glucan synthase inhibitor, cilofungin, amphotericin B and 5-fluorocytosine on opsonization, phagocytosis and intracellular killing of Candida albicans blastospores by glass-adherent human neutrophils was determined by microscopy and dye exclusion staining. Pretreatment of blastospores for 2, 4, 6 and 18 h with 1.25 mg/l cilofungin resulted in 24-28% of neutrophils ingesting compared to 24% with no drug present. There was no significant difference in the phagocytic index with increased incubation time. Percentage ingestion and phagocytic index values were not significantly different when blastospores were pretreated for 2 h in the presence of 3, 7, 15, 31 and 62 mg/l cilofungin. Comparable concentrations of amphotericin B and 5-fluorocytosine gave similar results. In the absence of cilofungin, intracellular killing after 2 h was 54%. In the presence of 1 and 10 mg/l cilofungin, 85-90% of intracellular blastospores were killed. Therapeutic levels of amphotericin B or 5-fluorocytosine did not enhance intracellular killing. These data demonstrate the potentiation of intracellular killing of Candida albicans by neutrophils in the presence of cilofungin.
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330
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Chechani V, Scott G, Burnham B, Knight L. Modification of an aerosol mask to provide high concentrations of oxygen in the inspired air. Comparison to a nonrebreathing mask. Chest 1991; 100:1582-5. [PMID: 1959399 DOI: 10.1378/chest.100.6.1582] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
With a few simple modifications, an aerosol mask was adapted to deliver high concentrations of oxygen. We compared the delivery of high concentrations of oxygen by this modified aerosol mask (MAM) with that of a nonrebreathing mask (NRM) in five normal volunteers and six patients with respiratory failure. Besides improved oxygenation, the MAM also permitted the following: humidification of the inspired oxygen, nebulization of bronchodilators, oropharyngeal suctioning, and performance of fiberoptic bronchoscopy. In lieu of intubation and mechanical ventilation, MAM may be a better alternative to a NRM for maintaining adequate oxygenation until the clinical situation improves.
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331
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Chechani V, Scott G. Pulse oximetry in evaluation of oxygen needs of patients with chronic obstructive pulmonary disease (COPD). MISSOURI MEDICINE 1991; 88:757-61. [PMID: 1805130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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332
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Dolowy WC, Lind JC, Scott G. Stereoscopic evaluation of specimens (technical tip). ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY 1991; 72:261-2. [PMID: 1923408 DOI: 10.1016/0030-4220(91)90175-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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333
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Abstract
Dihydroergotamine (DHE) is available in the United States for parenteral use. We report a preliminary trial of DHE suppositories in an outpatient headache clinic setting. Dihydroergotamine suppositories may be appropriate for patients with catamenial migraine and classic migraine in particular.
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334
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Scott G, Wilson DW, Bentley G. Roentgenographic assessment in hallux valgus. Clin Orthop Relat Res 1991:143-7. [PMID: 2044267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Which simple roentgenographic angle should be used to assess medial (varus) deviation of the first metatarsal in cases of hallux valgus has been a topic of debate. Measurements were made from roentgenograms of 100 symptomatic feet in women with hallux valgus. These were compared with similar measurements obtained from symptomatic normal feet of women of a similar age distribution. The hallux valgus angle was associated with medial deviation of the first metatarsal measured by all three of the parameters defined and tested, i.e., the intermetatarsal, metatarsus primus varus, and metatarsus omnis varus angles. Of these, the best measure was the intermetatarsal angle, which in the hallux valgus feet differed significantly from controls more than the other measurements. No evidence was found to support any concept of second metatarsal deviation from normal.
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335
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Nierenberg D, Harbaugh R, Maurer LH, Reeder T, Scott G, Fratkin J, Newman E. Continuous intratumoral infusion of methotrexate for recurrent glioblastoma: a pilot study. Neurosurgery 1991; 28:752-61. [PMID: 1652112 DOI: 10.1097/00006123-199105000-00023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Five patients with documented recurrences of glioblastoma multiforme were given continuous infusions of methotrexate delivered intratumorally using implantable catheters and subcutaneous refillable pumps. A continuous infusion of methotrexate (1 mg/d) was begun with concomitant oral administration of folinic acid. The methotrexate dose was increased every 2 weeks to 3, 10, 30, and, ultimately, 75 mg/d in two patients. Samples of serum and ventricular cerebrospinal fluid (CSF) were obtained to determine the levels of methotrexate and total bioactive folates, and brain tissue was obtained from two patients for determination of methotrexate concentration. The patients survived from 7 to 49 weeks after the implantation of the infusion device. Neither the clinical examination nor sequential radiological studies gave clear evidence of reduction in tumor size. Pneumonia developed in one patient, and mild hepatitis and increased seizure frequency in another. Methotrexate was stable in the delivery system over 12 days, and ventricular CSF reached steady-state levels by 5 days. Steady-state ventricular CSF levels of methotrexate were higher than serum levels in some patients, while the reverse was true in others. Levels of total bioactive folates in the CSF did not increase above the normal range. Methotrexate concentrations were highest at the center of the tumor, but measurable amounts of methotrexate were detectable in all areas of the brain. At autopsy in four patients, variable liquefactive necrosis of the brain tumors was seen, and viable tumor was found at the periphery of the tumor bed. These preliminary results suggest that it is technically feasible to infuse methotrexate into brain tumor cavities, and show that little central nervous system or systemic toxicity was encountered in five patients. Better delineation of the safety and efficacy of this therapeutic approach will require further clinical trials.
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336
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Scott G, Stoler M, Sarkar S, Halaban R. Localization of basic fibroblast growth factor mRNA in melanocytic lesions by in situ hybridization. J Invest Dermatol 1991; 96:318-22. [PMID: 2002252 DOI: 10.1111/1523-1747.ep12465203] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Basic fibroblast growth factor (bFGF) is a mitogen for normal human melanocytes and keratinocytes in culture. Experiments in vitro suggest that keratinocytes supply bFGF to melanocytes through a paracrine mechanism and that the aberrant expression of bFGF in melanomas confers growth independence from bFGF-producing cells. To determine whether bFGF is expressed in vivo, we examined a series of benign and malignant melanocytic lesions in situ using bFGF riboprobes on tissue sections, and correlated bFGF expression with histologic phenotype. Seventeen melanocytic neoplasms were studied, including four common acquired nevi, four dysplastic nevi, four primary malignant melanomas, and five metastatic melanomas. Nevic cells in benign intradermal nevi showed low signal intensity (1+), whereas compound and dysplastic nevi showed 2+ to 3+ expression in the junctional nevic cell population and 1+ expression in the dermal nevic cell population. Melanocytes in primary melanomas had intermediate (2+) and those in metastatic melanomas had low (1+) levels of bFGF gene transcripts. Fibroblasts expressed high levels (3+) and epidermal and adnexal keratinocytes moderate (2+) levels of bFGF in all cases studied. Basic FGF expression in endothelial cells, known to produce and respond to this growth factor in vitro, was lower than that in the fibroblast and keratinocyte cell population and, in 10 of 17 cases, no bFGF mRNA was detectable. This study shows that bFGF is expressed in nevomelanocytes in vivo in all melanocytic lesions studied and thus cannot be used as a marker for transformation. The presence of bFGF gene transcripts in the various dermal cell types and in keratinocytes suggests that it may act as an autocrine and paracrine growth factor in regulating cellular proliferation in the skin.
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337
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Al-Malaika S, Goonetileka M, Scott G. Migration of 4-substituted 2-hydroxy benzophenones in low density polyethylene: Part I—Diffusion characteristics. Polym Degrad Stab 1991. [DOI: 10.1016/0141-3910(91)90053-t] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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338
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Birch R, Jessop J, Scott G. Brachial plexus palsy after manipulation of the shoulder. THE JOURNAL OF BONE AND JOINT SURGERY. BRITISH VOLUME 1991; 73:172. [PMID: 1991758 DOI: 10.1302/0301-620x.73b1.1991758] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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339
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Banfield PJ, Scott G, Roberts HR. A modified contraceptive diaphragm for relief of uretero-vaginal fistula. Case report. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1991; 98:101-2. [PMID: 1998617 DOI: 10.1111/j.1471-0528.1991.tb10319.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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340
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Finter NB, Chapman S, Dowd P, Johnston JM, Manna V, Sarantis N, Sheron N, Scott G, Phua S, Tatum PB. The use of interferon-alpha in virus infections. Drugs 1991; 42:749-65. [PMID: 1723372 PMCID: PMC7100942 DOI: 10.2165/00003495-199142050-00003] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The interferons (IFN) act too slowly to arrest acute viral infections, but interferon-alpha (IFN alpha) preparations have proved useful in some chronic infections and will clearly be used increasingly in these in the future. In the preparations derived from human leucocytes or cultured B lymphoblastoid cells, which are in routine clinical use, mixtures of a number of distinct subtypes of human IFN alpha have been identified. There are also 3 slightly different versions of the same single subtype, IFN alpha-2, made by recombinant DNA procedures in bacteria. IFN alpha preparations are injected intramuscularly or subcutaneously. Dose-related side effects are common but usually tolerable, but prolonged treatment may cause increasing fatigue and depression. Some patients form neutralising antibodies which block the effects of the IFN; these appear to be relatively more common after recombinant IFN alpha-2 than after IFN derived from human cells. Given intranasally, IFN alpha can prevent a subsequent experimental rhinovirus infection, or the spread of natural colds within a family. Repeated administration progressively damages the nasal mucosa, so that long term prophylaxis is not possible. IFN alpha has proved useful in patients with papillomavirus warts of the larynx, ano-genital region (condyloma acuminata) and skin (common warts). Treatment regimens remain to be optimised and are likely to include surgery or other treatments. IFN alpha and zidovudine (azidothymidine) synergistically inhibit the growth of HIV in vitro, and combination are on trial in patients with early AIDS. Very large doses of IFN alpha are effective against Kaposi's sarcoma in some AIDS patients. In chronic hepatitis B, continuing virus replication may lead to cirrhosis or primary liver cancer. Earlier clinical trials with IFN alpha gave inconclusive results, but recent large studies have confirmed that 25 to 40% of patients obtain benefit; this probably results from both the antiviral and the immunomodulatory effects of IFN alpha. In patients with chronic hepatitis C, the biochemical markers usually improve rapidly during IFN alpha administration, but relapse if treatment is stopped after only a few months; to increase the chances of sustained cure, the treatment period is now being prolonged.
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Abstract
A national sample of 1500 mothers of 1-year-old children received a postal questionnaire concerned with the sleeping patterns of their children. The response rate was 69%. Seventeen per cent of mothers reported that their 1-year-old presented a moderate or severe sleep problem and 26% said their child woke at night on at least five nights a week. While these two measures correlated, 10% of those who reported their infant woke on at least five nights a week did not consider this to be a problem. Neither sex of infant, social class, method of infant feeding or numbers of house moves were associated with sleep problems. The pattern of results strongly suggest an association between night waking and other sleeping difficulties and stress for mothers. This was indicated by the association we found with complaints about housing, overcrowding, more negative attitudes toward motherhood, lower assessments of maternal well-being, lack of practical support from partners, the use of more negative adjectives to describe their baby and more frequent feelings of being dominated by their baby. While these associations may be explained by the stresses of living with a night-waking baby, it is also likely that a mother who is feeling somewhat depressed and negative toward her baby is more likely to see night waking as significant and as a problem. There were class differences in how parents coped with a shortage of space. Middle-class parents were more likely to put a baby in with a sibling while working class parents more often had the baby in their own room. Middle-class parents were more likely to leave a night-waking baby to cry.
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342
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Webb JG, Butany J, Langer G, Scott G, Liu PP. Myocarditis and myocardial hemorrhage associated with thrombotic thrombocytopenic purpura. ACTA ACUST UNITED AC 1990. [PMID: 2369253 DOI: 10.1001/archinte.1990.00390190167029] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Four patients with thrombotic thrombocytopenic purpura (TTP) developed severe cardiac dysfunction. Endomyocardial biopsy in one patient demonstrated focal myocarditis associated with platelet microthrombi. Cardiac function and TTP improved after plasmapheresis therapy in this as well as in two other patients. A fourth patient died owing to extensive intramyocardial confluent hemorrhages. Cardiac involvement in TTP may be due to microvascular thrombosis, hemorrhage, or myocarditis. Severe myocardial dysfunction may improve with treatment aimed at the underlying hematologic disorder.
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343
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Noll ML, Hix CD, Scott G. Closed tracheal suction systems: effectiveness and nursing implications. AACN CLINICAL ISSUES IN CRITICAL CARE NURSING 1990; 1:318-28. [PMID: 2206731 DOI: 10.4037/15597768-1990-2010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Closed tracheal suction systems (CTSS) are currently being used to minimize complications associated with endotracheal suctioning. Advantages of CTSS include improved oxygenation, decreased clinical signs of hypoxemia, maintenance of positive end-expiratory pressure, infection control, convenience, cost, and reduced patient anxiety. Some concerns related to use of CTSS include autocontamination, decreased effectiveness, difficult to use, excess negative pressure, and airway trauma. Strategies for reducing these and other concerns are shared. Recommendations for nursing practice and nursing research are discussed.
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Abstract
A randomized controlled study was conducted with three groups of mothers with night waking infants less than 18 mths. Groups received a specially written advice booklet and support visits, the booklet only or no intervention. A fourth group of non-night waking infants acted as a comparison group. Mothers' estimates of waking frequency and infant sleep diaries and maternal well being measures were used to assess change. No significant differences in terms of outcome measures were found between three waking groups. Mothers of night wakers showed higher levels of distress than those in the sleeping group. Parents of wakers were positive about both the support they had received and the booklet.
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345
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Braun S, Lee B, Conrad E, Scott G, Goldenheim P. Incidence and clinical correlates of nocturnal awakening secondary to dyspnea in chronic obstructive airway disease (COAD). Chest 1990. [DOI: 10.1378/chest.97.3.80s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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346
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Mehta RL, Scott G, Sloand JA, Francis CW. Skin necrosis associated with acquired protein C deficiency in patients with renal failure and calciphylaxis. Am J Med 1990; 88:252-7. [PMID: 2309740 DOI: 10.1016/0002-9343(90)90150-c] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE To determine if the natural anticoagulant protein C plays a role in the pathogenesis of systemic calciphylaxis, a syndrome characterized by extensive vascular and soft tissue calcification and skin necrosis, which is similar to that seen in warfarin-induced skin necrosis. PATIENTS AND METHODS The study population included five patients with end-stage renal disease and systemic calciphylaxis undergoing hemodialysis, 12 patients without evidence of calciphylaxis undergoing dialysis, eight patients with nephrotic syndrome, and eight normal healthy volunteers. Protein C antigen levels were measured by rocket immunoelectrophoresis, and functional activity was quantitated by a chromogenic assay and an anticoagulant assay utilizing the venom of Agkistrodon contortrix. RESULTS Skin biopsy specimens of involved areas in three patients showed thrombotic occlusion of venules identical to that seen in warfarin-induced skin necrosis. Protein C antigen levels were normal in all groups. However, protein C activity was significantly reduced as measured by chromogenic (p less than 0.01) or anticoagulant assays (p less than 0.01) in patients with calciphylaxis compared with the other three groups. CONCLUSION These findings suggest that hypercoagulability due to functional protein C deficiency may contribute to thrombosis, resulting in skin necrosis and digital gangrene in systemic calciphylaxis.
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347
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Lawson JP, Scott G. Case report 602: Spindle cell hemangioendothelioma (SCH) and enchondromatosis (a form of Maffucci syndrome) in a patient with acute myelocytic leukemia (AML). Skeletal Radiol 1990; 19:158-62. [PMID: 2321048 DOI: 10.1007/bf00197630] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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348
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Parker GD, Jones NR, Scott G. Cervical myelopathy in C.P.P.D. deposition disease. AUSTRALASIAN RADIOLOGY 1990; 34:82-5. [PMID: 2162659 DOI: 10.1111/j.1440-1673.1990.tb02815.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cervical Myelopathy is a rare manifestation of calcium pyrophosphate dihydrate (C.P.P.D.) deposition disease. A case is presented where radiographically noncalcified extradural masses containing C.P.P.D. crystals were present at the C7 level, producing cord compression and neurological symptoms. These masses are thought to represent para-articular deposits related to the adjacent facet joints.
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349
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Scott G, Thompson R, Dixon A, Sacco A. The role of triethanolamine in zeolite crystallization. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0144-2449(90)90093-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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350
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Simpson DA, Blumbergs PC, Cooter RD, Kilminster M, McLean AJ, Scott G. Pontomedullary tears and other gross brainstem injuries after vehicular accidents. THE JOURNAL OF TRAUMA 1989; 29:1519-25. [PMID: 2585563 DOI: 10.1097/00005373-198911000-00011] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In a series of 988 autopsied victims of road crashes, there were 36 (3.6%) cases of gross primary brainstem injury. These fell into three groups. The first comprised eight cases of pontomedullary tearing without other gross brain injury: in seven of these, there were associated atlanto-occipital dislocations and/or high cervical fracture-dislocations. The usual cause appeared to be facial impact inducing acute hyperextension. Second, there were 17 cases of pontomedullary tearing associated with other brainstem lacerations and/or major damage elsewhere in the brain: in all, there were fractures of the skull base, typically transverse middle fossa fractures. Most of these injuries appeared to be due to facial impacts transmitting force to the anterior skull base, although hyperextension was also a factor in some. There was a third heterogeneous group of 11 cases with brainstem lacerations in sites other than the pontomedullary junction: in some of these it appeared that the impacts had caused skull base fractures by inducing calvarial torsion. In this series, the proportion of motorcyclists (41.7%) was double the expected figure. The use of a helmet modifies the mechanisms of impact head injury; the overall benefits of helmet use are well established, but there is need for more research on helmet design.
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