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Abstract
A 39-year-old man developed sequential acute mononeuropathies involving both median, both ulnar, and the right radial and left peroneal nerves. Electrophysiology demonstrated an asymmetric sensorimotor axonal polyneuropathy; nerve biopsy confirmed a vasculitis. Laboratory evaluation revealed a mixed cryoglobulinemia and active hepatitis C infection. The patient stabilized with prednisone/cyclophosphamide/interferon-alpha. Hepatitis C should be considered in the differential diagnosis of mononeuropathy multiplex. Accurate diagnosis is important, as interferon-alpha may prevent transition to chronic hepatitis/cirrhosis.
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302
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Miller RG, Bryan WW, Dietz MA, Munsat TL, Petajan JH, Smith SA, Goodpasture JC. Toxicity and tolerability of recombinant human ciliary neurotrophic factor in patients with amyotrophic lateral sclerosis. Neurology 1996; 47:1329-31. [PMID: 8909453 DOI: 10.1212/wnl.47.5.1329] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We examined the toxicity of both single and multiple subcutaneous injections of recombinant human ciliary neurotrophic factor (rhCNTF) in 72 patients with ALS, in doses ranging from 2 to 100 micrograms/kg. Adverse events were generally dose related and ranged from mild to severe. The tolerability of daily subcutaneous rhCNTF was equivalent to placebo at doses < or = 5 micrograms/kg/day. At higher doses, anorexia, weight loss, reactivation of herpes simplex virus (HSV1) labialis/stomatitis, cough, and increased oral secretions occurred.
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303
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Shepherd D, Smith SA. Central projections of persistent larval sensory neurons prefigure adult sensory pathways in the CNS of Drosophila. Development 1996; 122:2375-84. [PMID: 8756283 DOI: 10.1242/dev.122.8.2375] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have used a GAL4 enhancer-trap line driving the expression of a lacZ construct to examine the reorganisation of an identified group of proprioceptive sensory neurons during metamorphosis in Drosophila. The results show that whilst most larval sensory neurons degenerate during the first 24 hours of metamorphosis a segmentally repeated array of 6 neurons per segment persists into the adult stages to become functional adult neurons. These sensory neurons retain their axonal projections in the central nervous system intact and unchanged throughout. The adult sensory neuron axons enter the central nervous system at around 44 hours after puparium formation. Most of these axons grow along the pathways defined by the persistent larval sensory axons. The ordering of the adult sensory projections is, therefore, established upon the larval pattern of projections. The possibility that the larval neurons act as guidance cues for organising the ordered arrays of sensory neurons is discussed.
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304
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Strickland D, Smith SA, Dolliff G, Goldman L, Roelofs RI. Amyotrophic lateral sclerosis and occupational history. A pilot case-control study. ARCHIVES OF NEUROLOGY 1996; 53:730-3. [PMID: 8759978 DOI: 10.1001/archneur.1996.00550080044011] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To assess the association of a number of occupational and industrial exposures with amyotrophic lateral sclerosis (ALS). DESIGN A case-control study of ALS cases matched by age and sex to 2 controls each: 1 from a neurologic clinic and 1 from a local community. Exposures were ascertained by questionnaire, and patients were requested before the interview to be to prepared to supply occupational histories. SETTING Patients with ALS were enrolled at the University of Minnesota ALS Clinic in Minneapolis. PATIENTS Patients with ALS (n = 25) were from the University of Minnesota ALS clinic, and clinic controls (n = 25) were patients with other neuromuscular diseases from the university's Muscle Disease Clinic, selected on the basis of clinic enrollment date nearest to that of the matched case. Clinic controls were principally patients with myopathies. Community controls (n = 25) were selected from the community using a random-digit-dialing protocol matching on the first 5 digits of the case patient's telephone number. RESULTS The strongest association with disease was exposure to welding or soldering materials (odds ratio, 5.0) and the welding industry (odds ratio, 5.3). Electric plating showed a high odds ratio of 8 (95% confidence interval, 0.9-72.0), but low statistical significance (P < .07) Several exposures or industries, while not statistically different, showed enough difference that to ignore them might lead to a Type II error, a result of the pilot nature and small sample size. These included paint or pigment manufacturing, the petroleum industry, the printing industry, and shipbuilding. CONCLUSIONS The association with welding, soldering, and the welding industry is strong and suggests a need for further work. This is despite the small numbers studied, thus making most industrial or occupational exposures too limited to draw conclusions or detect associations. Perhaps the most obvious candidate from the welding, soldering exposure for a common toxin would be lead. Other suggestions of risk were seen for paint or pigment manufacture, shipbuilding, electric plating, and the dairy industry. The degree of association for these, while high, is not statistically significant, and suggests that there may be 1 or more environmental toxins common to those industries that need more precise measurement.
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305
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Strickland D, Smith SA, Dolliff G, Goldman L, Roelofs RI. Physical activity, trauma, and ALS: a case-control study. Acta Neurol Scand 1996; 94:45-50. [PMID: 8874593 DOI: 10.1111/j.1600-0404.1996.tb00038.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
AIMS The association of trauma and physical activity with ALS is controversial. We explored the relation in a pilot case-control study. MATERIAL AND METHODS ALS patients were selected from a university muscle disease clinic and paired with two matched controls: one from the clinic, but having different diseases, and one from the community. RESULTS We found several strong and statistically significant differences between ALS cases and the matched controls. These included severe head, neck and back injury (OR = 5.3), the frequency of sweating in work (OR = 1.6) or leisure activity (also OR = 1.6), and earning a school letter (OR = 3.1). Other measures of trauma and activity, while not achieving statistical significance (p < 0.05), were in accord with these findings. DISCUSSION Possible explanations include trauma and vigorous exercise precipitating ALS; trauma as an early sign of disease; or a third factor associated with ALS predisposing to injury. CONCLUSIONS Severe head, neck, and back injury and frequency of sweating both in work and leisure activity showed a strong association with ALS. Further study could test narrower and less common exposures with greater statistical power.
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306
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Boyfield I, Brown TH, Coldwell MC, Cooper DG, Hadley MS, Hagan JJ, Healy MA, Johns A, King RJ, Middlemiss DN, Nash DJ, Riley GJ, Scott EE, Smith SA, Stemp G. Design and synthesis of 2-naphthoate esters as selective dopamine D4 antagonists. J Med Chem 1996; 39:1946-8. [PMID: 8642552 DOI: 10.1021/jm960017l] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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307
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Pearson SL, Liu YL, Davenport M, Smith SA, Dunmore SJ. Reduced insulin sensitivity of isolated skeletal muscle but enhanced lipogenic capacity of adipocytes in both spontaneously hypertensive and Wistar Kyoto rats. Biochem Soc Trans 1996; 24:234S. [PMID: 8736892 DOI: 10.1042/bst024234s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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308
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Hrubec TC, Smith SA, Robertson JL, Feldman B, Veit HP, Libey G, Tinker MK. Blood biochemical reference intervals for sunshine bass (Morone chrysops x Morone saxatilis) in three culture systems. Am J Vet Res 1996; 57:624-7. [PMID: 8723871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To determine and compare biochemical reference intervals for sunshine bass (hybrid striped bass) from 3 culture systems. DESIGN Observational comparison study. ANIMALS Clinically normal sunshine bass (reciprocal hybrid striped bass, female Morone chrysops x male M saxatilis raised in high-density recirculating systems (80 g/L), low-density tanks (5 g/L) with biofilters, and cages (70 g/L) in a fresh water pond. PROCEDURE Biochemical reference intervals were determined for fish from the different production systems following the National Committee for Clinical Laboratory Standards guidelines. Reference intervals from the 3 groups were compared. RESULTS Reference intervals were significantly different between sunshine bass in the various culture systems. Though most of the differences in reference intervals were minor, fish in the high-density recirculating system had higher concentrations of total protein, albumin, globulin, creatinine, and phosphorus, and lower chloride values. There were no significant differences in glucose concentrations among the 3 groups of fish, and no differences in cortisol concentrations between fish in tanks and cages. CONCLUSIONS Separate reference intervals should be developed for hybrid striped bass in different culture systems. CLINICAL RELEVANCE Determining biochemical reference intervals for hybrid striped bass provides a tool to assess the health status of these fish.
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309
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Sidaway JE, Dickson AJ, Smith SA, Boam DS. Effect of the thiazolidinedione antihyperglycaemic agent BRL 49653 on liver fatty acid binding protein gene expression. Biochem Soc Trans 1996; 24:231S. [PMID: 8736889 DOI: 10.1042/bst024231s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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310
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Hrubec TC, Smith SA, Robertson JL, Feldman B, Veit HP, Libey G, Tinker MK. Comparison of hematologic reference intervals between culture system and type of hybrid striped bass. Am J Vet Res 1996; 57:618-23. [PMID: 8723870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To determine and compare hematologic reference intervals for hybrid striped bass from different culture systems and for 2 types of hybrid. DESIGN Observational comparison study. ANIMALS Clinically normal sunshine bass (reciprocal hybrid striped bass, female Morone chrysops X male M saxatilis) raised in high-density recirculating systems, sunshine bass raised in tanks with biofilters, and palmetto bass (original hybrid striped bass, female M saxatilis X male M chrysops) raised in tanks with biofilters. PROCEDURES Hematologic reference intervals were determined for fish from the different production systems, following the National Committee for Clinical Laboratory Standards guidelines. Reference intervals from the 3 groups were compared. RESULTS Reference intervals were significantly different between sunshine bass in the 2 culture systems and between sunshine and palmetto bass. Many of the differences were slight, but notable differences were observed. Sunshine bass in recirculating systems had higher total leukocyte, lymphocyte, neutrophil, and monocyte counts than did either hybrid in tanks. Palmetto bass had a greater number of neutrophils than monocytes, whereas sunshine bass had more monocytes than neutrophils. Additionally, palmetto bass had a lower PCV and hemoglobin value than did either group of sunshine bass. CONCLUSIONS Separate reference intervals should be developed for hybrid striped bass in different culture systems and for different types of hybrids. CLINICAL RELEVANCE Determining reference intervals for hybrid striped bass provides a tool to assess the health status of these fish.
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311
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Albertsen HM, Smith SA, Melis R, Williams B, Holik P, Stevens J, White R. Sequence, genomic structure, and chromosomal assignment of human DOC-2. Genomics 1996; 33:207-13. [PMID: 8660969 DOI: 10.1006/geno.1996.0185] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
DOC-2 is a human gene originally identified as a 767-bp cDNA fragment isolated from normal ovarian epithelial cells by differential display against ovarian carcinoma cells. We have now determined the complete cDNA sequence of the 3.2-kb DOC-2 transcript and localized the gene to chromosome 5. A 12.5-kb genomic fragment at the 5'-end of DOC-2 has also been sequenced, revealing the intron-exon structure of the first eight exons (788 bases) of the DOC-2 gene. Translation of the DOC-2 cDNA predicts a hydrophobic protein of 770 amino acid residues with a molecular weight of 82.5 kDa. Comparison of the DNA and amino acid sequences of DOC-2 to publicly accessible sequence databases revealed 83% identify to p96, a murine protein of similar size, thought to be a mitogen-responsive phosphoprotein. In addition, about 45% identity was observed between the first 140 N-terminal residues of DOC-2 and the Caenorhabditas elegans M110.5 and Drosophila melanogaster Dab genes.
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312
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313
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Miller RG, Smith SA, Murphy JR, Brinkmann JR, Graves J, Mendoza M, Sands ML, Ringel SP. A clinical trial of verapamil in amyotrophic lateral sclerosis. Muscle Nerve 1996; 19:511-5. [PMID: 8622731 DOI: 10.1002/mus.880190405] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Seventy-two patients with amyotrophic lateral sclerosis (ALS) were enrolled in a clinical trial of the efficacy of verapamil in the treatment of ALS. In period 1 (pretreatment, months 1-3) and period 3 (posttreatment, months 10-12), patients received no drug. In period 2 (months 4-9), patients received verapamil. The slopes of declining pulmonary function and limb megascores were not significantly different during drug treatment compared to natural history and washout periods. Thus, verapamil was ineffective in slowing the clinical progression in ALS patients. Controlled trials using a natural history period may represent a faster and less expensive method of screening drugs for ALS compared to placebo-controlled trials.
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314
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Hrubec TC, Robertson JL, Smith SA, Tinker MK. The effect of temperature and water quality on antibody response to Aeromonas salmonicida in sunshine bass (Morone chrysops x Morone saxatilis). Vet Immunol Immunopathol 1996; 50:157-66. [PMID: 9157680 DOI: 10.1016/0165-2427(95)05491-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The kinetics of the antibody response to Aeromonas salmonicida were determined in sunshine bass (hybrid striped bass: female Morone chrysops X male Morone saxatilis) acclimated to 10, 18, 24, 29 degrees C, and to 0.15 mg 1(-1) un-ionized ammonia and 200 mg 1(-1) nitrate levels. Temperature and water quality factors affected the immune response of sunshine bass. Temperatures of 10 degrees C and 18 degrees C decreased the magnitude and delayed the time of the antibody response to A. salmonicida. The antibody response was not affected at 29 degrees C, which is above the optimal temperature for sunshine bass. Elevated un-ionized ammonia concentrations of 0.15 mg 1(-1) also did not affect the antibody response. Elevated nitrate levels of 200 mg 1(-1), however, decreased the antibody response to the same extent as 18 degrees C water.
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315
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Sombeck MD, Kalbaugh KJ, Mendenhall WM, Parsons JT, Smith SA, Million RR, Palta JR. Radiotherapy for early vocal cord cancer: a dosimetric analysis of 60CO versus 6 MV photons. Head Neck 1996; 18:167-73. [PMID: 8647683 DOI: 10.1002/(sici)1097-0347(199603/04)18:2<167::aid-hed9>3.0.co;2-#] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Currently, many patients with early vocal cord cancers are treated with 6 MV photons, but almost all the published radiotherapy data are based on patients treated with 60Co, 2-MV, or 4-MV X-rays. A theoretical risk of underdosage exists with higher energy beams due to lack of dose build-up. This dosimetric study compares 6-MV photons with 60Co. METHODS A tissue-equivalent phantom was constructed of a stack of 0.5-cm-thick acrylic plates. With a male subject in treatment position as the model, the external surfaces of the phantom were machined to match the contour of the neck. To precisely represent the internal contour of the airway, computed tomography (CT) was performed on the subject in treatment position, with images at 0.5-cm intervals, and the airway shown on the CT was cut out of each corresponding acrylic plate. Thermoluminescent dosimetry (TLD) rods were inserted into the phantom. For each measurement, a calculated tumor dose of 10 Gy was delivered to the volume specified as the entire right true vocal cord in the phantom, with either 60Co or 6-MV photons (15 measurements were made with each). In a second series of eight experiments with each modality, TLD minichips were used to measure the dose received by the immediate surface of the vocal cords with delivery of a calculated tumor dose of 0.5 Gy. RESULTS The doses received at the vocal cords, as well as a point 6 mm beneath the anterior skin surface, did not differ significantly for the two energies compared. The dose delivered to the skin and a point 3 mm beneath the anterior skin surface was significantly lower with the use of 6-MV photons. CONCLUSION Although there is no difference in the dose received by the vocal cords, underdosage of the anterior tissues may occur with the use of 6-MV photons.
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316
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Smith SA. Comparison of two screening tests of competency to stand trial for defendants with mental retardation. Psychol Rep 1996; 78:234. [PMID: 8839314 DOI: 10.2466/pr0.1996.78.1.234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Scores for the four terms found by Smith and Hudson to predict competency to stand trial in defendants with mental retardation correlated significantly (r = .65) with scores on the Competency Screening Test (N = 34). Agreement between sets of scores was 84%.
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317
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Smith SA, Holik P, Stevens J, Mazoyer S, Melis R, Williams B, White R, Albertsen H. Isolation of a gene (DLG3) encoding a second member of the discs-large family on chromosome 17q12-q21. Genomics 1996; 31:145-50. [PMID: 8824795 DOI: 10.1006/geno.1996.0025] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The discs-large family is a collection of proteins that have a common structural organization and are thought to be involved in signal transduction and mediating protein-protein interactions at the cytoplasmic surface of the cell membrane. The defining member of this group of proteins is the gene product of the Drosophila lethal (1) discs large (dlg) 1 locus, which was originally identified by the analysis of recessive lethal mutants. Germline mutations in dlg result in loss of apical-basolateral polarity, disruption of normal cell-cell adhesion, and neoplastic overgrowth of the imaginal disc epithelium. We have isolated and characterized a novel human gene, DLG3, that encodes a new member of the discs-large family of proteins. The putative DLG3 gene product has a molecular weight of 66 kDa and contains a discs-large homologous region, a src oncogene homology motif 3, and a domain with homology to guanylate kinase. The DLG3 gene is located on chromosome 17, in the same segment, 17q12-q21, as the related gene, DLG2. The products of the DLG2 and DLG3 genes show 36% identity and 58% similarity to each other, and both show nearly 60% sequence similarity to p55, an erythroid phosphoprotein that is a component of the red cell membrane. We suggest that p55, DLG2, and DLG3 are closely related members of a gene family, whose protein products have a common structural organization and probably a similar function.
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318
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Smith SA, Shepherd D. Central afferent projections of proprioceptive sensory neurons in Drosophila revealed with the enhancer-trap technique. J Comp Neurol 1996; 364:311-23. [PMID: 8788252 DOI: 10.1002/(sici)1096-9861(19960108)364:2<311::aid-cne9>3.0.co;2-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have used a GAL4 enhancer-trap line coupled with an upstream activation sequence (UAS)-linked lacZ reporter construct to visualise and describe the central projections of proprioceptive sensory neurons of the thorax and abdomen in Drosophila. In the legs, lacZ expression is restricted to sensory neurons associated with hair plates, a subset of campaniform sensilla, and with the femoral chordotonal organ; whereas, in the wing, expression is seen only in subsets of campaniform sensilla. In the abdomen, expression is seen in Wheeler's organ and in a segmentally repeated array of internal sensory neurons that have not been previously described. The central projections from all of these neurons are described. The results confirm and expand upon our knowledge of the organisation of sensory neuropils in insects. The enhancer-trap technique provides a potentially powerful tool for describing the organisation of the central nervous system of Drosophila.
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319
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Smith SA. Persistent microvasculopathy in chronic eosinophilia-myalgia syndrome. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 398:359-64. [PMID: 8906289 DOI: 10.1007/978-1-4613-0381-7_55] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Acute eosinophilia-myalgia syndrome (EMS) due to contaminated L-tryptophan (LT) exposure is an inflammatory microangiopathy of the dermis, fascia, and muscle. Select individuals evolve from acute EMS to have persistence of myalgia, fatigue, cramps, and skin changes for years. Many develop memory dysfunction and confusion. The objective of this study is to delineate the pathology in individuals with chronic EMS. Seventeen patients with ongoing symptoms representing chronic EMS are studied by skin, fascia, and muscle biopsies four to five years after exposure to contaminated LT and initial onset of EMS. All have microvascular disease. Most have lymphocytic inflammatory infiltrates. Several have dermal sclerosis. The findings indicate that persistent microvascular disease is present in chronic EMS. The pathologic changes are similar to those of acute EMS but with notable differences. Tissue eosinophil infiltration is rare in the chronic state as compared to acute EMS. The persistence of endothelial pathology indicates continuing microvascular dysfunction.
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MESH Headings
- Arterioles/pathology
- Arterioles/ultrastructure
- Biopsy
- Capillaries/pathology
- Capillaries/ultrastructure
- Drug Contamination
- Endothelium, Vascular/pathology
- Endothelium, Vascular/ultrastructure
- Eosinophilia-Myalgia Syndrome/pathology
- Follow-Up Studies
- Humans
- Microscopy, Electron
- Muscle, Skeletal/blood supply
- Muscle, Skeletal/pathology
- Muscle, Skeletal/ultrastructure
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/ultrastructure
- Necrosis
- Skin/blood supply
- Skin/pathology
- Time Factors
- Tryptophan/adverse effects
- Tryptophan/standards
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320
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Braekevelt CR, Smith BJ, Smith SA. Fine structure of the retinal pigment epithelium of the barred owl (Strix varia). Histol Histopathol 1996; 11:71-7. [PMID: 8720449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The retinal pigment epithelium (RPE) as well as the choriocapillaris and Bruch's membrane (complexus basalis) have been studied by light and electron microscopy in the barred owl (Strix varia). The RPE consists of a single layer of cuboidal cells joined laterally by a series of tight junctions that forms part of the blood-ocular barrier. Basally (sclerally) the retinal epithelial cells display numerous deep infoldings while apically (vitreally) microvillar processes interdigitate with the photoreceptor outer segments. Internally the RPE cells show a large vesicular nucleus, plentiful smooth endoplasmic reticulum (SER) and polysomes but very little rough endoplasmic reticulum (RER). Numerous pleomorphic (including ring-shaped) mitochondria are basally located. In the light-adapted state the small melanosomes are almost exclusively located within the apical process indicating that retinomotor movements probably occur. Phagosomes and lysosome-like bodies are present as are myeloid bodies which may show ribosomes on their outer surface. Bruch's membrane is typical of avian species in that it is pentalaminate and the central lamina densa is displaced towards the choroid. The choriocapillaris endothelium is thin but only minimally fenestrated facing Bruch's membrane. Most fenestrations present show a single-layered diaphragm while others display a double-layered diaphragm as noted in other avian species.
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321
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Braekevelt CR, Smith SA, Smith BJ. Fine structure of the retinal photoreceptors of the barred owl (Strix varia). Histol Histopathol 1996; 11:79-88. [PMID: 8720450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The photoreceptors of the barred owl (Strix varia) consist of rods, single cones and unequal double cones present in a ratio of about 35:1:3. In the light-adapted condition the rods are of uniform diameter along their entire length and are therefore not felt to undergo photomechanical changes. The rod outer segment consists of a stack of scalloped bimembranous discs enclosed in a limiting membrane. The rod inner segment displays an ellipsoid of mitochondria, much rough endoplasmic reticulum (RER), numerous polysomes, Golgi zones and autophagic vacuoles, but no hyperboloid of glycogen. Single cones show a slightly tapered outer segment and a heterogeneous oil droplet along with an ellipsoid of mitochondria at the apex of the inner segment. Double cones consist of a larger chief member which also displays a heterogeneous oil droplet and a slightly smaller accessory member which does not. Both members of the double cone as well as the single cones show plentiful polysomes and RER as well as Golgi zones in the inner segment, but none of the cones possessed a condensed paraboloid of glycogen. The contiguous membranes of the chief and accessory cones displayed a few presumed junctional complexes. Judging by their elongated shape in the light-adapted state, cones in this species do not undergo retinomotor movements. Rods and both types of cones have both invaginated (ribbon) and superficial (conventional) synaptic sites.
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322
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Smith BJ, Smith SA, Braekevelt CR. Fine structure of the pecten oculi of the barred owl (Strix varia). Histol Histopathol 1996; 11:89-96. [PMID: 8720451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The pecten oculi of the barred owl (Strix varia) has been examined by light and transmission electron microscopy. The pecten in this species is of the pleated type and is small in comparison to the size of the ocular globe. The pecten consists of 8-10 accordion-like folds that are linked apically by a pigmented tissue bridge. Each fold contains numerous capillaries, larger supply and drainage vessels, and abundant pleomorphic melanocytes. Most of these capillaries are extremely specialized vessels that possess plentiful microfolds on both the luminal and abluminal surfaces. Some capillaries however display only a few microfolds. The endothelial cell bodies are extremely attenuated, with most organelles located near the nucleus. All capillaries are surrounded by a very thick fibrillar basal lamina, which is thought to provide structural support to these small vessels. Pericytes are commonly found within these thickened basal laminae. Numerous melanocytes are also present, with processes that form an incomplete sheath around the capillaries. These processes are also presumed to provide structural support for the capillaries. As in other avian species, the morphology of the barred owl pecten is indicative of extensive involvement in substance transport. When compared to the pecten of more visually-oriented species, this pecten is smaller, has fewer folds, and displays a reduced number of microfolds within the capillaries. In these and other features, the barred owl pecten is similar to the pecten of the great horned owl (Bubo virginianus).
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323
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Smith SA, Jett PL, Jacobson SL, Binder ND, Kuforiji TA, Gilhooly JT, Piatt JH, Pillers DA, Reynolds JW, Benda GI. Subgaleal hematoma: the need for increased awareness of risk. THE JOURNAL OF FAMILY PRACTICE 1995; 41:569-574. [PMID: 7500066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Subgaleal hematoma, also known as subaponeurotic hemorrhage, is a serious complication of birth that is associated with vacuum-assisted delivery. Despite a high rate of mortality associated with subgaleal hematoma, it has received relatively little attention in the medical literature. Lack of awareness may lead to delayed diagnosis and serious consequences for infants. This paper is a report of six cases and a literature review. Prevention and early recognition and treatment of the condition can occur only with increased practitioner awareness of this entity.
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324
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Smith SA. Patient-induced dehydration--can it ever be therapeutic? Oncol Nurs Forum 1995; 22:1487-91. [PMID: 8577617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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325
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Dominguez AM, Smith SA, Greenbaum IF. Susceptibility of heterochromatin to aphidicolin-induced chromosomal breakage. Hum Genet 1995; 96:516-20. [PMID: 8529996 DOI: 10.1007/bf00197404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The distribution of aphidicolin-induced chromosomal lesions was analyzed to determine the relative breakage susceptibility of euchromatin and heterochromatin in the cactus mouse, Peromyscus eremicus. The observed breakage was tested against expected distributions corresponding to the karyotypic proportions of autosomal euchromatin, autosomal heterochromatin, X-chromosomal euchromatin, and X-chromosomal heterochromatin. The distribution of induced breakage was independent of sex but dependent on the individual. In all individuals, there was a highly significant (P < < 0.0001) deficiency in the number of breaks observed as compared to expected in autosomal heterochromatin. Sparse observations in the X chromosome and the absence of breaks in the Y chromosome precluded valid statistical tests of the sex-chromosomal distribution of induced breakage. These data indicate that the autosomal heterochromatin of Peromyscus is resistant to aphidicolin-induced chromosomal breakage and argue against a simple relationship between late replication and a general mechanism for chromosomal fragility.
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