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1.
Plant Dis ; 103(6): 1138-1147, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30939059

ABSTRACT

In western Colorado, Cytospora leucostoma is ubiquitous in peach orchards and has developed into a major limiting factor of peach production. The pathogen is unable to invade healthy intact phloem tissue of the tree, but instead, it requires a wound as a mode of entry. Bark injuries caused by cold and pruning in commercial orchard systems provide infection courts that, in suitable environment conditions, can lead to many successful fungal infections. Preventive fungicide control is an integral component of management in tree fruit production. Eighteen fungicides were tested at selected label dose rates for C. leucostoma control. All treatments were initially tested in vitro in fungicide-amended media dishes. Successful treatments were then tested under controlled conditions on detached peach branch segments. Effective fungicides identified in the laboratory assays (thiophanate-methyl, captan, lime sulfur, and copper hydroxide) were further tested as spray applications in the field and as wound sealant applications in combination with latex paint and kaolin clay. Of the treatments evaluated, thiophanate-methyl, captan, 50% latex paint, thiophanate-methyl amended in 50% latex paint, captan amended in 50% latex paint, and lime sulfur were most effective in reducing C. leucostoma necrotic area. Copper hydroxide was ineffective in all field trials and in some instances, yielded larger necrotic areas than the nontreated positive control shoots.


Subject(s)
Ascomycota , Fungicides, Industrial , Prunus persica , Ascomycota/physiology , Colorado , Fungicides, Industrial/pharmacology , Plant Diseases/prevention & control , Prunus persica/microbiology
2.
J Pediatr ; 139(6): 785-9, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11743502

ABSTRACT

OBJECTIVE: The Stroke Prevention Trial (STOP) demonstrated that chronic transfusion is highly effective in reducing the risk of stroke in children with sickle-cell disease and an abnormal transcranial Doppler ultrasonography examination result. Our objective was to determine whether chronic transfusion therapy reduces the incidence of pain and acute chest syndrome. METHODS: During STOP, 130 children with sickle-cell anemia or sickle beta(0)-thalassemia and abnormal transcranial Doppler ultrasonography examination result were randomly assigned to chronic transfusion (n = 63) or observation (n = 67). In addition to monitoring for stroke, nonneurologic sickle-cell complications were identified and recorded. RESULTS: Mean age at STOP study entry was 8.3 +/- 3.3 years, and mean follow-up was 19.6 +/- 6.5 months. Hospitalization rates (based on intent-to-treat analysis) for acute chest syndrome were 4.8 and 15.3 per 100 patient-years (P =.0027) and for pain were 16.2 and 27.6 per 100 patient-years (P =.13) in the chronic transfusion and observed groups, respectively. If analyzed according to treatment actually received, the difference in pain rate becomes significant (9.7 vs 27.1 events per 100 patient-years, P =.014), and transfusion remains protective from acute chest syndrome (2.2 vs 15.7 events per 100 patient-years, P =.0001). CONCLUSIONS: Compliance with aggressive chronic transfusion reduces the frequency of acute chest syndrome and pain episodes.


Subject(s)
Anemia, Sickle Cell/therapy , Blood Transfusion , Chest Pain/prevention & control , Life Tables , Pain/prevention & control , Stroke/prevention & control , Adolescent , Anemia, Sickle Cell/blood , Anemia, Sickle Cell/complications , Chest Pain/blood , Chest Pain/etiology , Child , Child, Preschool , Female , Hemoglobin, Sickle/analysis , Hospitalization , Humans , Male , Pain/blood , Pain/etiology , Patient Compliance , Regression Analysis , Stroke/diagnostic imaging , Stroke/etiology , Ultrasonography, Doppler, Transcranial
3.
J Pediatr ; 139(3): 385-90, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11562618

ABSTRACT

OBJECTIVE: To determine whether children with homozygous sickle cell anemia (SCD) who have silent infarcts on magnetic resonance imaging (MRI) of the brain are at increased risk for overt stroke. METHODS: We selected patients with homozygous SCD who (1) enrolled in the Cooperative Study of Sickle Cell Disease (CSSCD) before age 6 months, (2) had at least 1 study-mandated brain MRI at age 6 years or older, and (3) had no overt stroke before a first MRI. MRI results and clinical and laboratory parameters were tested as predictors of stroke. RESULTS: Among 248 eligible patients, mean age at first MRI was 8.3 +/- 1.9 years, and mean follow-up after baseline MRI was 5.2 +/- 2.2 years. Five (8.1%) of 62 patients with silent infarct had strokes compared with 1 (0.5%) of 186 patients without prior silent infarct; incidence per 100 patient-years of follow-up was increased 14-fold (1.45 per 100 patient-years vs 0.11 per 100 patient-years, P =.006). Of several clinical and laboratory parameters examined, silent infarct was the strongest independent predictor of stroke (hazard ratio = 7.2, P =.027). CONCLUSIONS: Silent infarct identified at age 6 years or older is associated with increased stroke risk.


Subject(s)
Anemia, Sickle Cell/complications , Myocardial Infarction/complications , Stroke/etiology , Child , Humans , Infant , Magnetic Resonance Imaging , Myocardial Infarction/diagnosis , Risk Factors
4.
J Ambul Care Manage ; 24(3): 37-44, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11433554

ABSTRACT

African Americans often have interactions with health care systems, services, and providers that are quite different from those of other population groups. Residents in a predominantly African American community in the southeastern United States identified issues that had a significant influence on their health care interactions. Their insights about health insurance concerns, perceived quality of health care, and trust in the health care system provide a useful framework for the redesign of care that will better meet their health care needs.


Subject(s)
Black or African American/psychology , Patient Acceptance of Health Care/ethnology , Quality of Health Care/organization & administration , Cardiovascular Diseases , Diabetes Mellitus , Focus Groups , Health Priorities , Humans , Insurance, Health , Organizational Innovation , Physician-Patient Relations , Southeastern United States , Tennessee
5.
J Mol Biol ; 307(2): 499-512, 2001 Mar 23.
Article in English | MEDLINE | ID: mdl-11254378

ABSTRACT

A genetic algorithm-based computational method for the ab initio phasing of diffraction data from crystals of symmetric macromolecular structures, such as icosahedral viruses, has been implemented and applied to authentic data from the P1/Mahoney strain of poliovirus. Using only single-wavelength native diffraction data, the method is shown to be able to generate correct phases, and thus electron density, to 3.0 A resolution. Beginning with no advance knowledge of the shape of the virus and only approximate knowledge of its size, the method uses a genetic algorithm to determine coarse, low-resolution (here, 20.5 A) models of the virus that obey the known non-crystallographic symmetry (NCS) constraints. The best scoring of these models are subjected to refinement and NCS-averaging, with subsequent phase extension to high resolution (3.0 A). Initial difficulties in phase extension were overcome by measuring and including all low-resolution terms in the transform. With the low-resolution data included, the method was successful in generating essentially correct phases and electron density to 6.0 A in every one of ten trials from different models identified by the genetic algorithm. Retrospective analysis revealed that these correct high-resolution solutions converged from a range of significantly different low-resolution phase sets (average differences of 59.7 degrees below 24 A). This method represents an efficient way to determine phases for icosahedral viruses, and has the advantage of producing phases free from model bias. It is expected that the method can be extended to other protein systems with high NCS.


Subject(s)
Algorithms , Capsid/ultrastructure , Crystallography, X-Ray/methods , Poliovirus/chemistry , Capsid/chemistry , Models, Molecular , Models, Structural , Models, Theoretical , Poliovirus/ultrastructure
6.
J Pediatr Hematol Oncol ; 23(9): 623-5, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11902310

ABSTRACT

Persistent fever with pancytopenia and hepatomegaly with negative blood cultures and no obvious focus of infection in a child with Down syndrome should arouse a suspicion of leukemia. Bone marrow examination and clot biopsy from one such patient revealed hemophagocytosis and granulomas, with serologic evidence of recent Epstein-Barr virus infection. Bone marrow granulomas are not a feature of Epstein-Barr infection. Later, bone marrow culture and repeat blood culture grew Salmonella typhi. Thus, in a febrile child, when performing a bone marrow aspirate, a clot biopsy and culture for infectious etiology may be helpful, even when leukemia is strongly suspected.


Subject(s)
Bone Marrow/pathology , Down Syndrome/complications , Epstein-Barr Virus Infections/complications , Granuloma/pathology , Histiocytosis, Non-Langerhans-Cell/pathology , Pancytopenia/etiology , Salmonella typhi/isolation & purification , Typhoid Fever/pathology , Bacteremia/complications , Bacteremia/microbiology , Bone Marrow/microbiology , Child, Preschool , Diagnosis, Differential , Down Syndrome/pathology , Epstein-Barr Virus Infections/diagnosis , Epstein-Barr Virus Infections/pathology , Granuloma/etiology , Hepatomegaly/etiology , Hepatomegaly/pathology , Histiocytosis, Non-Langerhans-Cell/diagnosis , Humans , Leukemia/diagnosis , Male , Splenomegaly/etiology , Splenomegaly/pathology , Staphylococcal Infections/complications , Staphylococcal Infections/microbiology , Typhoid Fever/complications , Typhoid Fever/microbiology , Urinary Tract Infections/complications , Urinary Tract Infections/microbiology
7.
Prev Med ; 31(5): 513-21, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11071831

ABSTRACT

BACKGROUND: Although many primary care patients are inactive, being able to classify even small amounts and intensities of activity and factors associated with these activity levels could be helpful for physicians who are trying to motivate their patients to become more physically active. METHODS: Sociodemographics, physical activity, fitness, other cardiovascular risk factors, and psychosocial measures were measured at baseline in the 874 patients in the Activity Counseling Trial. Patients were categorized into three groups: (1) no moderate-to-vigorous physical activity (MVPA), (2) some moderate but no vigorous activity, and (3) some vigorous activity. Multiple logistic regression was used to determine factors cross-sectionally associated with activity intensity. RESULTS: One or more cardiovascular risk factors in addition to physical inactivity were present in 84% of participants. Maximal oxygen uptake averaged 25.2 ml/kg/min; 85% had poor to fair aerobic fitness. Physical activity averaged 32.7 kcal/kg/day, with 13.5 min of MVPA/day; 26% engaged in some vigorous activity, 11% engaged in no MVPA. In unadjusted analyses, gender, age, race, education, income, employment, smoking, alcohol use, and exercise self-efficacy were associated with activity intensity (P = 0.05-0.001). A greater percentage engaged in moderate than in vigorous activity in all subgroups. In multiple logistic regression analyses, odds ratios (95% confidence intervals) for engaging in vigorous activity were 0. 39 (0.28, 0.56) for women, 0.38 (0.19, 0.75) for 65+ compared with 35- to 44-year-olds, and 1.14 (1.06, 1.22) for 10-unit increases in performance self-efficacy score. CONCLUSIONS: Most primary care patients who are physically inactive have additional cardiovascular risk factors, particularly overweight and obesity. All subgroups pursue moderate-intensity activity more often than vigorous activity. Women, older persons, and those with lower exercise self-efficacy are less likely to engage in vigorous activity.


Subject(s)
Counseling , Exercise , Health Promotion , Primary Health Care , Adult , Aged , Cholesterol/blood , Cross-Sectional Studies , Female , Humans , Hypertension/complications , Logistic Models , Male , Middle Aged , Obesity/complications , Physical Fitness , Risk Factors , Smoking/adverse effects , Socioeconomic Factors
8.
J Assoc Acad Minor Phys ; 11(2-3): 21-7, 2000.
Article in English | MEDLINE | ID: mdl-10953540

ABSTRACT

This study tested the hypothesis that diminished exocrine pancreatic function observed in Cu(2+)-deficient rats is associated with alterations in the cholecystokinin (CCK) signal transduction pathway. Male Sprague-Dawley rats were maintained on either a control diet (11 ppm Cu2+) or a Cu(2+)-deficient diet containing 6000 ppm triethylenetetramine tetrahydrochloride. For the duration of the study rats had free access to water and food. After 4 weeks, rats were sacrificed and pancreatic acini isolated for measurement of amylase content, cholecystokinin-stimulated amylase release and total inositol phosphate formation. Plasma Cu2+ levels were significantly (P < 0.05) decreased in rats on a Cu(2+)-deficient diet (19.2 +/- 3.4 micrograms Cu2+/dL), compared with the control diet (77.0 +/- 3.5 micrograms Cu2+/dL). Both amylase content of pancreatic acini and total CCK-8-stimulated amylase release were significantly decreased in Cu(2+)-deficient rats. In addition, Cu(2+)-deficient rats exhibited a decrease (153.5 +/- 30.9%) in the magnitude of CCK-8-stimulated total inositol phosphate formation compared with control rats (220.8 +/- 11.9%). Moreover, CCKA receptor affinity on pancreatic membranes was not significantly altered by Cu(2+)-deficiency, while CCKA receptor density was significantly (P < 0.05) decreased in Cu(2+)-deficient rats. The addition of Cu2+ to the binding assay of Cu(2+)-deficient rats did not restore receptor density to control values. The data demonstrates that adequate dietary intake of Cu2+ is important to maintain the functional integrity of the exocrine pancreas.


Subject(s)
Cholecystokinin/metabolism , Copper/deficiency , Pancreas/enzymology , Pancreas/metabolism , Signal Transduction/physiology , Amylases/metabolism , Animals , Inositol Phosphates/metabolism , Male , Rats , Rats, Sprague-Dawley
9.
N Engl J Med ; 342(2): 83-9, 2000 Jan 13.
Article in English | MEDLINE | ID: mdl-10631276

ABSTRACT

BACKGROUND: The ability to identify infants with sickle cell anemia who are likely to have severe complications later in life would permit accurate prognostication and tailoring of therapy to match disease-related risks and facilitate planning of clinical trials. We attempted to define the features of such babies by following the clinical course of 392 children with sickle cell disease from infancy to about the age of 10 years. METHODS: We analyzed the records of 392 infants who received the diagnosis of homozygous sickle cell anemia or sickle cell-Beta(0)-thalassemia before the age of six months and for whom comprehensive clinical and laboratory data were recorded prospectively; data were available for a mean (+/-SD) of 10.0+/-4.8 years. Results obtained before the age of two years were evaluated to determine whether they predicted the outcome later in life. RESULTS: Of the 392 infants in the cohort, 70 (18 percent) subsequently had an adverse outcome, defined as death (18 patients [26 percent]), stroke (25 [36 percent]) frequent pain (17 [24 percent]), or recurrent acute chest syndrome (10 [14 percent]). Using multivariate analysis, we found three statistically significant predictors of an adverse outcome: an episode of dactylitis before the age of one year (relative risk of an adverse outcome, 2.55; 95 percent confidence interval, 1.39 to 4.67), a hemoglobin level of less than 7 g per deciliter (relative risk, 2.47; 95 percent confidence interval, 1.14 to 5.33), and leukocytosis in the absence of infection (relative risk, 1.80; 95 percent confidence interval, 1.05 to 3.09). CONCLUSIONS: Three easily identifiable manifestations of sickle cell disease that may appear in the first two years of life (dactylitis, severe anemia, and leukocytosis) can help to predict the possibility of severe sickle cell disease later in life.


Subject(s)
Anemia, Sickle Cell/classification , Anemia, Sickle Cell/complications , Anemia/etiology , Anemia, Sickle Cell/mortality , Cohort Studies , Extremities , Humans , Infant , Inflammation/etiology , Leukocytosis/etiology , Logistic Models , Multivariate Analysis , Pain/etiology , Prognosis , ROC Curve , Retrospective Studies , Severity of Illness Index , Stroke/etiology , beta-Thalassemia/classification , beta-Thalassemia/complications
10.
Acta Ophthalmol Scand Suppl ; (228): 33-7, 1999.
Article in English | MEDLINE | ID: mdl-10337430

ABSTRACT

Two important realizations about pathophysiological mechanisms involved in allergic conjunctivitis have led to novel drug discovery efforts and new topical ocular medications for prevention and treatment of this prevent allergic disease. The first of these, interspecies and intraspecies mast cell heterogeneity, was established in the mid-1980's by investigators working in the field of asthma. It is now appreciated that secretory responses as well as effects of pharmacological agents differ depending upon the mast cell population studied. Two types of human mast cells, the tryptase containing (T) and the tryptase/chymase containing (TC) mast cells, have been characterized in a variety of tissues. Significantly, Irani et al. (1) demonstrated by immunohistochemical staining that the mast cells present in conjunctival tissues from patients with allergic conjunctivitis were 100% TC. Functional responses of human conjunctival mast cells to a variety of secretagogues (2) were consistent with their classification as TC or connective tissue type mast cells. Importantly, the studies by Miller et al. mentioned above allowed the harvesting and preparation of human conjunctival mast cells for use in drug screening studies. Utilization of these cells has led to the identification of Patanol, the most effective human conjunctival mast cell stabilizer available for topical use in allergic conjunctivitis (3). These same studies demonstrated the lack of mast cell stabilizing activity for cromolyn and nedocromil in these connective tissue type, TC containing, human conjunctival mast cells. Similar lack of effect was noted with these drugs on human skin mast cell degranulation (4). The second important discovery in the area of allergic conjunctivitis has been the demonstration that conjunctival epithelial cells may contribute to the perpetuation of the allergic response. A report from Gamache et al. (5) identified cytokines produced by human conjunctival epithelial cells following treatment with a number of stimuli. Significantly, Sharif et al. (6) subsequently identified functional histamine H1 receptors on these same cell types. Recently, Weimer et al. (7) have shown that exposure of human conjunctival epithelial cells to histamine leads to the production of pro-inflammatory cytokines IL-6 and IL-8. Importantly, treatment of the epithelial cells with drugs that possess histamine H1 antagonist properties prevents cytokine production. It is noteworthy that first generation anti-histamines antazoline and pheniramine are not potent inhibitors of histamine-stimulated cytokine synthesis in intact epithelial cells, while newer anti-histamines Emadine and levocabastine are more potent. Surprisingly, Patanol was more potent as an inhibitor of histamine-stimulated cytokine production by the epithelial cells than would be predicted from its histamine H1 antagonist affinity. These inhibitory effects on conjunctival epithelial cell production of pro-inflammatory cytokines may contribute to enhanced clinical activity noted with these recently approved drugs.


Subject(s)
Conjunctivitis, Allergic/drug therapy , Anti-Allergic Agents/therapeutic use , Conjunctivitis, Allergic/immunology , Cytokines/metabolism , Drug Therapy, Combination , Epithelial Cells/immunology , Histamine H1 Antagonists/therapeutic use , Histamine Release/drug effects , Humans , Mast Cells/immunology , Ophthalmic Solutions , Vasoconstrictor Agents/therapeutic use
11.
Pediatrics ; 103(3): 640-5, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10049969

ABSTRACT

BACKGROUND: Silent infarcts have been reported in 17% of young patients with sickle cell disease and are associated with impaired performance on standardized psychometric tests. Risk factors for the development of these lesions have not been identified. METHODS: Investigators in the Cooperative Study of Sickle Cell Disease performed a brain magnetic resonance imaging scan on sickle cell anemia patients age 5.9 years and older who had been followed according to the protocols of the Cooperative Study since birth. Individuals with a known history of cerebrovascular accident were excluded from this analysis. Patients with and without silent infarctions were compared with regard to clinical and laboratory parameters. RESULTS: The study sample included 42 patients (18.3%) with silent infarcts. Patients who had silent infarcts were significantly more likely to have a clinical history of seizure and a lower painful event rate. Lower hemoglobin level, increased leukocyte count, elevated pocked red blood cell count, and SEN betaS globin gene haplotype were associated also with the presence of silent infarcts. There was no relationship between silent infarcts and platelet count, fetal hemoglobin level, reticulocyte percentage, serum aspartate aminotransferase level, total bilirubin concentration, blood pressure, growth parameters, or presence of alpha-thalassemia. A multivariate model for silent infarction identified the following as risk factors: low pain event rate, history of seizure, leukocyte count >/=11.8 x 10(9)/L, and the SEN betaS globin gene haplotype. CONCLUSIONS: Patients with risk factors for silent infarcts should be evaluated for cerebrovascular disease. If evidence of infarction is found, consideration must be given to therapeutic intervention. At present, the appropriate treatment has not been determined.


Subject(s)
Anemia, Sickle Cell/complications , Cerebral Infarction/etiology , Adolescent , Child , Child, Preschool , Female , Humans , Male , Multivariate Analysis , Risk Factors
12.
Am J Physiol ; 275(5): G993-8, 1998 11.
Article in English | MEDLINE | ID: mdl-9815029

ABSTRACT

We have previously demonstrated that altered exocrine pancreatic stimulus-secretion coupling is associated with ovariectomy and chronic estradiol administration. To elucidate possible mechanisms underlying those effects we examined the ability of chronic administration of different doses of estradiol to regulate the CCK signal transduction pathway in isolated rat pancreatic acini. Doses of estradiol ranging from 0.5 to 119 micrograms/day were administered to ovariectomized rats for 18 days. Ovariectomy was associated with enhanced CCK-stimulated pancreatic amylase release, whereas estradiol dose dependently decreased the magnitude of CCK-stimulated amylase release. Ovariectomy was also associated with enhanced CCK receptor numbers on acinar cell membranes. Estradiol administration was associated with dose-dependent decreases in CCK receptor numbers. Neither ovariectomy nor estradiol administration affected CCK receptor affinity. Moreover, estradiol administration was associated with increased expression of the alpha-subunit of the heterotrimeric G protein Gq/11 (Galphaq/11). Recent findings (H. Ohnishi, S. A. Ernst, D. I. Yule, C. W. Baker, and J. A. Williams. J. Biol. Chem. 272: 16056-16061, 1997) demonstrate that Galphaq/11 may exert a tonic inhibitory effect on pancreatic enzyme release. In view of these findings, the increased expression of Galphaq/11 induced by estradiol likely contributes to the inhibition of pancreatic enzyme release. We conclude that the effect of estradiol to decrease pancreatic secretion is mediated through regulation of CCK receptor density and Galphaq/11 expression.


Subject(s)
Cholecystokinin/physiology , Estradiol/pharmacology , Pancreas/physiology , Receptors, Cholecystokinin/physiology , Amylases/metabolism , Animals , Cell Membrane/metabolism , Cholecystokinin/pharmacology , Down-Regulation/drug effects , Estradiol/physiology , Female , GTP-Binding Proteins/biosynthesis , GTP-Binding Proteins/genetics , In Vitro Techniques , Iodine Radioisotopes , Ovariectomy , Pancreas/drug effects , Radioligand Assay , Rats , Rats, Sprague-Dawley , Receptors, Cholecystokinin/biosynthesis , Sincalide/metabolism
14.
J Biomed Mater Res ; 41(1): 1-7, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9641618

ABSTRACT

This study was designed to investigate the in vivo biodegration and biocompatibility of a poly(propylene fumarate) (PPF)-based orthopedic biomaterial. The effects of varying the PPF to N-vinyl pyrrolidinone ratio and PPF to beta-tricalcium phosphate content were studied. The composite mechanical properties and local tissue interactions were analyzed over 12 weeks. An initial increase in both compressive modulus and strength was seen for composite formulations that incorporated beta-tricalcium phosphate. The samples incorporating a higher PPF to N-vinyl pyrrolidinone ratio reached a maximal compressive strength of 7.7 MPa and a maximal compressive modulus of 191.4 MPa at 3 weeks. The lower PPF to N-vinyl pyrrolidinone ratio samples gained a maximum compressive strength of 7.5 MPa initially and a compressive modulus of 134.0 MPa at 1 week. At 6 weeks, all samples for formulations incorporating beta-tricalcium phosphate crumbled upon removal and were not mechanically tested. Samples that did not incorporate beta-tricalcium phosphate were very weak and insufficient for bone replacement at the 4-day time point and beyond. Tissue interactions resulted in a mild inflammatory response at the initial time points and mature fibrous encapsulation by 12 weeks.


Subject(s)
Biocompatible Materials/metabolism , Calcium Phosphates/metabolism , Composite Resins/metabolism , Fumarates/metabolism , Polypropylenes/metabolism , Animals , Biocompatible Materials/adverse effects , Biodegradation, Environmental , Bone Regeneration , Calcium Phosphates/adverse effects , Composite Resins/adverse effects , Fumarates/adverse effects , Guided Tissue Regeneration , Inflammation/chemically induced , Male , Materials Testing , Polypropylenes/adverse effects , Rats , Rats, Inbred Lew
15.
Invest Ophthalmol Vis Sci ; 39(2): 336-43, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9477991

ABSTRACT

PURPOSE: To isolate and purify mast cells and epithelial cells from human cadaveric donor conjunctival tissue and to characterize interactions between these cell types in vitro. METHODS: Monodispersed cell suspensions obtained by enzymatic digestion of conjunctival tissue were applied to a single-density Percoll gradient. Epithelial cells obtained from the top layer of the gradient were cultured to confluence. Mast cells obtained from the pellet were equilibrated in culture medium and further purified using a two-step Percoll gradient. Using reverse transcription-polymerase chain reaction (RT-PCR), RNA from the purified mast cell preparation was probed for tumor necrosis factor-alpha (TNF alpha) message. Fluorescence activated cell sorting (FACS) analysis of intracellular immunostained mast cells was used to detect the TNF alpha protein. An examination for intercellular adhesion molecule 1 (ICAM-1) on epithelial cells was performed after 24-hour incubations with either recombinant TNF alpha supernatants from calcium ionophore A23187 (CaI)-stimulated mast cells or appropriate controls using FACS analysis. RESULTS: Highly purified human conjunctival mast cells and epithelial cells (each > 95%) were obtained from human cadaveric donor tissue. RT-PCR analysis of purified mast cell RNA revealed the expression of TNF alpha mRNA. An evaluation of mast cells for intracellular protein demonstrated positive staining for tryptase and TNF alpha. ICAM-1 was found on purified epithelial cells, and incubation of epithelial cell monolayers with supernatants from Cal-stimulated mast cells resulted in upregulation of this receptor. This upregulation was blocked by incubation with TNF alpha-neutralizing antibody. CONCLUSIONS: This work provides the methods for isolating and purifying mast cells and epithelial cells from human donor tissue and the opportunity for studying mechanisms of conjunctival inflammation by evaluating the interactions between these cells.


Subject(s)
Conjunctiva/cytology , Epithelial Cells/metabolism , Intercellular Adhesion Molecule-1/metabolism , Mast Cells/physiology , Tumor Necrosis Factor-alpha/physiology , Calcimycin/pharmacology , Cell Separation , Cells, Cultured , Chymases , DNA Primers/chemistry , Epithelial Cells/drug effects , Flow Cytometry , Humans , Intercellular Adhesion Molecule-1/genetics , Ionophores/pharmacology , Mast Cells/chemistry , Mast Cells/ultrastructure , Polymerase Chain Reaction , RNA, Messenger/metabolism , Recombinant Proteins/pharmacology , Serine Endopeptidases/metabolism , Transcription, Genetic , Tryptases , Tumor Necrosis Factor-alpha/pharmacology , Up-Regulation
16.
Blood ; 91(1): 288-94, 1998 Jan 01.
Article in English | MEDLINE | ID: mdl-9414296

ABSTRACT

Cerebrovascular accident (CVA) is a major complication of sickle cell disease. The incidence and mortality of and risk factors for CVA in sickle cell disease patients in the United States have been reported only in small patient samples. The Cooperative Study of Sickle Cell Disease collected clinical data on 4,082 sickle cell disease patients enrolled from 1978 to 1988. Patients were followed for an average of 5.2 +/- 2.0 years. Age-specific prevalence and incidence rates of CVA in patients with the common genotypes of sickle cell disease were determined, and the effects of hematologic and clinical events on the risk of CVA were analyzed. The highest rates of prevalence of CVA (4.01%) and incidence (0.61 per 100 patient-years) were in sickle cell anemia (SS) patients, but CVA occurred in all common genotypes. The incidence of infarctive CVA was lowest in SS patients 20 to 29 years of age and higher in children and older patients. Conversely, the incidence of hemorrhagic stroke in SS patients was highest among patients aged 20 to 29 years. Across all ages the mortality rate was 26% in the 2 weeks after hemorrhagic stroke. No deaths occurred after infarctive stroke. Risk factors for infarctive stroke included prior transient ischemic attack, low steady-state hemoglobin concentration and rate of and recent episode of acute chest syndrome, and elevated systolic blood pressure. Hemorrhagic stroke was associated with low steady-state hemoglobin and high leukocyte count.


Subject(s)
Anemia, Sickle Cell/complications , Cerebrovascular Disorders/etiology , Adolescent , Adult , Anemia, Sickle Cell/epidemiology , Blood Pressure , Cerebrovascular Disorders/epidemiology , Chest Pain/epidemiology , Chest Pain/etiology , Child , Child, Preschool , Comorbidity , Follow-Up Studies , Hemoglobins/analysis , Humans , Incidence , Infant , Ischemic Attack, Transient/epidemiology , Ischemic Attack, Transient/etiology , Middle Aged , Prevalence , Risk Factors , Syndrome , alpha-Thalassemia/epidemiology
17.
Int Arch Allergy Immunol ; 114(2): 139-43, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9338607

ABSTRACT

BACKGROUND: Mast cells have been identified in the choroid of numerous species including man. However, functional studies involving these human mast cells have not been reported. In the current studies, the secretory response of human choroidal mast cells to various stimuli was examined using monodispersed choroidal cell preparations. METHODS: Monodispersed cell suspensions of human choroid were prepared from eye bank globes and the number, histamine content, and secretory response of mast cells in these preparations were determined. Choroids from 27 donors were used for these experiments. RESULTS: Cell suspensions contained an average of 15% mast cells. Mast cells stained positively with toluidine blue and exhibited the classical granular appearance upon electron microscopy. The amount of histamine contained in each mast cell was calculated to be 2.74+/-0.17 pg. Significant histamine release was observed following treatment with anti-human IgE, calcium ionophore A23187, concanavalin A, compound 48/80 and morphine. CONCLUSION: A method has been developed for obtaining monodispersed human choroidal mast cell preparations. The cells were functional as evidenced by their ability to release histamine upon immunological and nonimmunological stimulation. The degranulation noted following compound 48/80 and morphine challenge suggests that these human choroidal mast cells are analogous to connective tissue or chymase/tryptase-positive mast cells.


Subject(s)
Antigens, Surface , Choroid/cytology , Histamine Release , Mast Cells/immunology , Calcimycin/pharmacology , Cell Separation , Concanavalin A , Humans , Mast Cells/cytology , Mast Cells/drug effects , Membrane Glycoproteins/pharmacology , Morphine/pharmacology
18.
Clin Pediatr (Phila) ; 36(2): 75-8, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9118593

ABSTRACT

Alpha thalassemia trait (alpha-thal-1) is a common cause of microcytosis in black and Asian populations. A small amount of hemoglobin Barts (2-8%) is transiently present in affected infants at birth and detectable in many newborn screening laboratories; it is a fast-moving hemoglobin on electrophoresis. In order to determine whether a report of a "fast hemoglobin variant" on newborn hemoglobinopathy screening is associated with a diagnosis of alpha thalassemia trait, hemoglobin concentration, red blood cell indices, and peripheral blood smear examination were performed on 18 infants referred for hematologic evaluation of a "fast hemoglobin variant" on newborn screening. All 18 infants with this diagnosis referred for consultation were black; ages ranged from 24 to 86 days (median 40 days). Six of 18 infants (33%) were mildly anemic for age and all 18 were microcytic. The prevalence of a "fast variant" among infants born at our institution is 2.5%. In that conditions other than alpha-thal-1 that cause microcytosis in early infancy are very uncommon, we conclude that all 18 of our infants with a fast hemoglobin on newborn screening likely have alpha-thal-1. The newborn screening result is thus a commonly and readily available laboratory report that specifically supports a diagnosis of alpha-thal-1, a diagnosis with significant clinical and genetic implications that is usually made only by exclusion.


Subject(s)
Hemoglobins/analysis , alpha-Thalassemia/diagnosis , Humans , Infant , Infant, Newborn , alpha-Thalassemia/blood
19.
Am J Med Sci ; 313(1): 50-7, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9001166

ABSTRACT

The objective of this study was to determine the rate of bacteremia in young women admitted to the hospital with presumed pyelonephritis and compare it with other published rates. The study design was a retrospective, structured chart review and a review of published reports of bacteremic pyelonephritis. An urban county teaching hospital provided the setting for the study. The patients were nonpregnant women (n = 98) 44 years of age or younger who were without bladder dysfunction and who had not been admitted to an intensive care unit. Further criteria for participation included discharge with the diagnosis of acute pyelonephritis. Blood cultures were ordered for 69 women; the results of 64 were noted in the chart. Twenty-three women (35.9% of those cultured; 23.4% of all patients) were diagnosed with bacteremia. In patients for whom blood culture results were obtained, trends developed between those patients with bacteremia and those with complicated pyelonephritis, defined as a known or newly discovered genitourinary abnormality or a risk factor (P = 0.044), those who were black (P = .044), those with higher pulses on admission (P = .050), those with more white blood cells per high-powered field after urinalysis (P = 0.007), and those whose fever lasted longer (P = 0.033). Blood culture results were positive in two patients whose urine cultures were negative. This comparatively high bacteremia rate supports routine ordering of blood cultures for urban women suspected of having pyelonephritis.


Subject(s)
Bacteremia/epidemiology , Pyelonephritis/microbiology , Adolescent , Adult , Black or African American , Demography , Female , Hospitals, County , Hospitals, University , Hospitals, Urban , Humans , Medical History Taking , Medical Records , Patient Selection , Physical Examination , Pyelonephritis/classification , Retrospective Studies , Risk Factors , Tennessee , Urban Population , White People
20.
Ann Allergy Asthma Immunol ; 79(6): 541-5, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9433371

ABSTRACT

BACKGROUND: The concept of mast cell heterogeneity is well established. Recent data indicate that human conjunctival tissue mast cells and human connective tissue mast cells respond to various secretagogues in similar fashion. It is now recognized that different mast cell populations respond differently to anti-allergic drugs. OBJECTIVE: The purpose of the study is to compare the effects of three new ocular anti-allergic drugs (nedocromil, olopatadine, and pemirolast) on mediator release from the target human conjunctival mast cell population with those of cromolyn sodium. The affinity of the compounds for the histamine H1 receptor was also compared. METHODS: A monodispersed suspension of partially purified human conjunctival mast cells was prepared from cadaver conjunctival tissue. Mast cells (5 x 10(3)) were challenged with anti-human IgE in the presence or absence of test drugs, and histamine content of the cell supernatants was determined using a specific radioimmunoassay. H1 receptor binding activity was assessed using a radioligand binding assay. RESULTS: Cromolyn and pemirolast (100 nM to 1 mM) failed to significantly inhibit histamine release from human conjunctival mast cells using exposure times of 1 and 15 minutes prior to challenge. Using identical nedocromil concentrations and exposure times, statistically significant (P < .05) inhibition (28%) of histamine release was observed at only the 100 microM concentration and 1-minute exposure time. In contrast, olopatadine inhibited histamine release in a concentration-dependent fashion (r = 0.891, n = 59, IC50 = 653 microM). Only olopatadine exhibited significant H1 receptor binding activity at relevant concentrations (Ki = 36 nM, n = 13). CONCLUSIONS: These data indicate that olopatadine possesses anti-allergic activity in the appropriate targets for topical ocular anti-allergic drug therapy, human conjunctival mast cells. Coupled with the compound's antihistaminic activity, this suggests that olopatadine will have efficacy advantages in allergic conjunctivitis patients over the other drugs tested.


Subject(s)
Anti-Allergic Agents/pharmacology , Conjunctiva/drug effects , Mast Cells/drug effects , Administration, Topical , Anti-Allergic Agents/metabolism , Antibodies, Anti-Idiotypic/immunology , Dibenzoxepins/pharmacology , Histamine Release/drug effects , Humans , Mast Cells/metabolism , Nedocromil/pharmacology , Olopatadine Hydrochloride , Pyridines/pharmacology , Pyrimidinones/pharmacology , Receptors, Histamine H1/metabolism
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